Coulomb-interaction induced coupling of Landau levels in intrinsic and modulation-doped quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, J.; Stevens, C. E.; Zhang, H.

We have performed two-dimensional Fourier transform spectroscopy on intrinsic and modulation doped quantum wells in external magnetic fields up to 10 T. In the undoped sample, the strong Coulomb interactions and the increasing separations of the electron and hole charge distributions with increasing magnetic fields lead to a nontrivial in-plane dispersion of the magneto-excitons. Thus, the discrete and degenerate Landau levels are coupled to a continuum. The signature of this continuum is the emergence of elongated spectral line shapes at the Landau level energies, which are exposed by the multidimensional nature of our technique. Surprisingly, the elongation of the peaksmore » is completely absent in the lowest Landau level spectra obtained from the modulation doped quantum well at high fields.« less

Coulomb-interaction induced coupling of Landau levels in intrinsic and modulation-doped quantum wells

DOE PAGES

Paul, J.; Stevens, C. E.; Zhang, H.; ...

2017-06-28

We have performed two-dimensional Fourier transform spectroscopy on intrinsic and modulation doped quantum wells in external magnetic fields up to 10 T. In the undoped sample, the strong Coulomb interactions and the increasing separations of the electron and hole charge distributions with increasing magnetic fields lead to a nontrivial in-plane dispersion of the magneto-excitons. Thus, the discrete and degenerate Landau levels are coupled to a continuum. The signature of this continuum is the emergence of elongated spectral line shapes at the Landau level energies, which are exposed by the multidimensional nature of our technique. Surprisingly, the elongation of the peaksmore » is completely absent in the lowest Landau level spectra obtained from the modulation doped quantum well at high fields.« less

Coulomb-interaction induced coupling of Landau levels in intrinsic and modulation-doped quantum wells

NASA Astrophysics Data System (ADS)

Paul, J.; Stevens, C. E.; Zhang, H.; Dey, P.; McGinty, D.; McGill, S. A.; Smith, R. P.; Reno, J. L.; Turkowski, V.; Perakis, I. E.; Hilton, D. J.; Karaiskaj, D.

2017-06-01

We have performed two-dimensional Fourier transform spectroscopy on intrinsic and modulation doped quantum wells in external magnetic fields up to 10 T. In the undoped sample, the strong Coulomb interactions and the increasing separations of the electron and hole charge distributions with increasing magnetic fields lead to a nontrivial in-plane dispersion of the magneto-excitons. Thus, the discrete and degenerate Landau levels are coupled to a continuum. The signature of this continuum is the emergence of elongated spectral line shapes at the Landau level energies, which are exposed by the multidimensional nature of our technique. Surprisingly, the elongation of the peaks is completely absent in the lowest Landau level spectra obtained from the modulation doped quantum well at high fields.

Comprehensive lipidomic analysis of human plasma using multidimensional liquid- and gas-phase separations: Two-dimensional liquid chromatography-mass spectrometry vs. liquid chromatography-trapped-ion-mobility-mass spectrometry.

PubMed

Baglai, Anna; Gargano, Andrea F G; Jordens, Jan; Mengerink, Ynze; Honing, Maarten; van der Wal, Sjoerd; Schoenmakers, Peter J

2017-12-29

Recent advancements in separation science have resulted in the commercialization of multidimensional separation systems that provide higher peak capacities and, hence, enable a more-detailed characterization of complex mixtures. In particular, two powerful analytical tools are increasingly used by analytical scientists, namely online comprehensive two-dimensional liquid chromatography (LC×LC, having a second-dimension separation in the liquid phase) and liquid chromatography-ion mobility-spectrometry (LC-IMS, second dimension separation in the gas phase). The goal of the current study was a general assessment of the liquid-chromatography-trapped-ion-mobility-mass spectrometry (LC-TIMS-MS) and comprehensive two-dimensional liquid chromatography-mass spectrometry (LC×LC-MS) platforms for untargeted lipid mapping in human plasma. For the first time trapped-ion-mobility spectrometry (TIMS) was employed for the separation of the major lipid classes and ion-mobility-derived collision-cross-section values were determined for a number of lipid standards. The general effects of a number of influencing parameters have been inspected and possible directions for improvements are discussed. We aimed to provide a general indication and practical guidelines for the analyst to choose an efficient multidimensional separation platform according to the particular requirements of the application. Analysis time, orthogonality, peak capacity, and an indicative measure for the resolving power are discussed as main characteristics for multidimensional separation systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Diagnosis and treatment of unconsummated marriage in an Iranian couple.

PubMed

Bokaie, Mahshid; Khalesi, Zahra Bostani; Yasini-Ardekani, Seyed Mojtaba

2017-09-01

Unconsummated marriage is a problem among couples who would not be able to perform natural sexual intercourse and vaginal penetration. This disorder is more common in developing countries and sometimes couples would come up with non-technical and non-scientific methods to overcome their problem. Multi-dimensional approach and narrative exposure therapy used in this case. This study would report a case of unconsummated marriage between a couple after 6 years. The main problem of this couple was vaginismus and post-traumatic stress. Treatment with multi-dimensional approach for this couple included methods like narrative exposure therapy, educating the anatomy of female and male reproductive system, correcting misconceptions, educating foreplay, educating body exploring and non-sexual and sexual massage and penetrating the vagina first by women finger and then men's after relaxation. The entire stages of the treatment lasted for four sessions and at the one-month follow-up couple's satisfaction was desirable. Unconsummated marriage is one of the main sexual problems; it is more common in developing countries than developed countries and cultural factors are effective on intensifying this disorder. The use of multi-dimensional approach in this study led to expedite diagnosis and treatment of vaginismus.

Evaluation of comprehensive multidimensional separations using reversed-phase, reversed-phase liquid chromatography/mass spectrometry for shotgun proteomics.

PubMed

Nakamura, Tatsuji; Kuromitsu, Junro; Oda, Yoshiya

2008-03-01

Two-dimensional liquid-chromatographic (LC) separation followed by mass spectrometric (MS) analysis was examined for the identification of peptides in complex mixtures as an alternative to widely used two-dimensional gel electrophoresis followed by MS analysis for use in proteomics. The present method involves the off-line coupling of a narrow-bore, polymer-based, reversed-phase column using an acetonitrile gradient in an alkaline mobile phase in the first dimension with octadecylsilanized silica (ODS)-based nano-LC/MS in the second dimension. After the first separation, successive fractions were acidified and dried off-line, then loaded on the second dimension column. Both columns separate peptides according to hydrophobicity under different pH conditions, but more peptides were identified than with the conventional technique for shotgun proteomics, that is, the combination of a strong cation exchange column with an ODS column, and the system was robust because no salts were included in the mobile phases. The suitability of the method for proteomics measurements was evaluated.

Computational analysis of an aortic valve jet

NASA Astrophysics Data System (ADS)

Shadden, Shawn C.; Astorino, Matteo; Gerbeau, Jean-Frédéric

2009-11-01

In this work we employ a coupled FSI scheme using an immersed boundary method to simulate flow through a realistic deformable, 3D aortic valve model. This data was used to compute Lagrangian coherent structures, which revealed flow separation from the valve leaflets during systole, and correspondingly, the boundary between the jet of ejected fluid and the regions of separated, recirculating flow. Advantages of computing LCS in multi-dimensional FSI models of the aortic valve are twofold. For one, the quality and effectiveness of existing clinical indices used to measure aortic jet size can be tested by taking advantage of the accurate measure of the jet area derived from LCS. Secondly, as an ultimate goal, a reliable computational framework for the assessment of the aortic valve stenosis could be developed.

Multi-Dimensional Damage Detection

NASA Technical Reports Server (NTRS)

Gibson, Tracy L. (Inventor); Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor); Lewis, Mark E. (Inventor); Snyder, Sarah J. (Inventor); Medelius, Pedro J. (Inventor)

2016-01-01

Methods and systems may provide for a structure having a plurality of interconnected panels, wherein each panel has a plurality of detection layers separated from one another by one or more non-detection layers. The plurality of detection layers may form a grid of conductive traces. Additionally, a monitor may be coupled to each grid of conductive traces, wherein the monitor is configured to detect damage to the plurality of interconnected panels in response to an electrical property change with respect to one or more of the conductive traces. In one example, the structure is part of an inflatable space platform such as a spacecraft or habitat.

A multidimensional high performance liquid chromatography method coupled with amperometric detection using a boron-doped diamond electrode for the simultaneous determination of sulfamethoxazole and trimethoprim in bovine milk.

PubMed

Andrade, Leonardo S; de Moraes, Marcela C; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando; Cass, Quezia B

2009-11-10

The development and validation of a multidimensional HPLC method using an on-line clean-up column coupled with amperometric detection employing a boron-doped diamond (BDD) electrode for the simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in bovine milk are presented. Aliquots of pre-prepared skim-milk samples were directly injected into a RAM octyl-BSA column in order to remove proteins that otherwise would interfere with milk analysis. After exclusion of the milk proteins, SMX and TMP were transferred to the analytical column (an octyl column) and the separation of the compounds from one another and from other endogenous milk components was achieved. SMX and TMP were detected amperometrically at 1.25V vs. Ag/AgCl (3.0molL(-1) KCl). Results with good linearity in the concentration ranges 50-800 and 25-400microgL(-1) for SMX and TMP, respectively, were obtained and no fouling of the BDD electrode was observed within the experimental period of several hours. The intra- and inter-assay coefficients of variation were less than 10% for both drugs and the obtained LOD values for SMX and TMP were 25.0 and 15.0microgL(-1), respectively.

A SECOND-ORDER DIVERGENCE-CONSTRAINED MULTIDIMENSIONAL NUMERICAL SCHEME FOR RELATIVISTIC TWO-FLUID ELECTRODYNAMICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amano, Takanobu, E-mail: amano@eps.s.u-tokyo.ac.jp

A new multidimensional simulation code for relativistic two-fluid electrodynamics (RTFED) is described. The basic equations consist of the full set of Maxwell’s equations coupled with relativistic hydrodynamic equations for separate two charged fluids, representing the dynamics of either an electron–positron or an electron–proton plasma. It can be recognized as an extension of conventional relativistic magnetohydrodynamics (RMHD). Finite resistivity may be introduced as a friction between the two species, which reduces to resistive RMHD in the long wavelength limit without suffering from a singularity at infinite conductivity. A numerical scheme based on HLL (Harten–Lax–Van Leer) Riemann solver is proposed that exactlymore » preserves the two divergence constraints for Maxwell’s equations simultaneously. Several benchmark problems demonstrate that it is capable of describing RMHD shocks/discontinuities at long wavelength limit, as well as dispersive characteristics due to the two-fluid effect appearing at small scales. This shows that the RTFED model is a promising tool for high energy astrophysics application.« less

Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts from urban dust and diesel standard reference materials using a 2D-LC/2D-GC system.

PubMed

Ahmed, Trifa M; Lim, Hwanmi; Bergvall, Christoffer; Westerholm, Roger

2013-10-01

A multidimensional, on-line coupled liquid chromatographic/gas chromatographic system was developed for the quantification of polycyclic aromatic hydrocarbons (PAHs). A two-dimensional liquid chromatographic system (2D-liquid chromatography (LC)), with three columns having different selectivities, was connected on-line to a two-dimensional gas chromatographic system (2D-gas chromatography (GC)). Samples were cleaned up by combining normal elution and column back-flush of the LC columns to selectively remove matrix constituents and isolate well-defined, PAH enriched fractions. Using this system, the sequential removal of polar, mono/diaromatic, olefinic and alkane compounds from crude extracts was achieved. The LC/GC coupling was performed using a fused silica transfer line into a programmable temperature vaporizer (PTV) GC injector. Using the PTV in the solvent vent mode, excess solvent was removed and the enriched PAH sample extract was injected into the GC. The 2D-GC setup consisted of two capillary columns with different stationary phase selectivities. Heart-cutting of selected PAH compounds in the first GC column (first dimension) and transfer of these to the second GC column (second dimension) increased the baseline resolutions of closely eluting PAHs. The on-line system was validated using the standard reference materials SRM 1649a (urban dust) and SRM 1975 (diesel particulate extract). The PAH concentrations measured were comparable to the certified values and the fully automated LC/GC system performed the clean-up, separation and detection of PAHs in 16 extracts in less than 24 h. The multidimensional, on-line 2D-LC/2D-GC system eliminated manual handling of the sample extracts and minimised the risk of sample loss and contamination, while increasing accuracy and precision.

Prototype of an Interface for Hyphenating Distillation with Gas Chromatography and Mass Spectrometry

PubMed Central

Tang, Ya-Ru; Yang, Hui-Hsien; Urban, Pawel L.

2017-01-01

Chemical analysis of complex matrices—containing hundreds of compounds—is challenging. Two-dimensional separation techniques provide an efficient way to reduce complexity of mixtures analyzed by mass spectrometry (MS). For example, gasoline is a mixture of numerous compounds, which can be fractionated by distillation techniques. However, coupling conventional distillation with other separations as well as MS is not straightforward. We have established an automatic system for online coupling of simple microscale distillation with gas chromatography (GC) and electron ionization MS. The developed system incorporates an interface between the distillation condenser and the injector of a fused silica capillary GC column. Development of this multidimensional separation (distillation-GC-MS) was preceded by a series of preliminary off-line experiments. In the developed technique, the components with different boiling points are fractionated and instantly analyzed by GC-MS. The obtained data sets illustrate dynamics of the distillation process. An important advantage of the distillation-GC-MS technique is that raw samples can directly be analyzed without removal of the non-volatile matrix residues that could contaminate the GC injection port and the column. Distilling the samples immediately before the injection to the GC column may reduce possible matrix effects—especially in the early phase of separation, when molecules with different volatilities co-migrate. It can also reduce losses of highly volatile components (during fraction collection and transfer). The two separation steps are partly orthogonal, what can slightly increase selectivity of the entire analysis. PMID:28337400

Simulation of a Multidimensional Input Quantum Perceptron

NASA Astrophysics Data System (ADS)

Yamamoto, Alexandre Y.; Sundqvist, Kyle M.; Li, Peng; Harris, H. Rusty

2018-06-01

In this work, we demonstrate the improved data separation capabilities of the Multidimensional Input Quantum Perceptron (MDIQP), a fundamental cell for the construction of more complex Quantum Artificial Neural Networks (QANNs). This is done by using input controlled alterations of ancillary qubits in combination with phase estimation and learning algorithms. The MDIQP is capable of processing quantum information and classifying multidimensional data that may not be linearly separable, extending the capabilities of the classical perceptron. With this powerful component, we get much closer to the achievement of a feedforward multilayer QANN, which would be able to represent and classify arbitrary sets of data (both quantum and classical).

Coupled LC-GC techniques for the characterisation of polycyclic aromatic compounds in fuel materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Askey, S.A.; Holden, K.M.L.; Bartle, K.D.

1995-12-31

Exposure to polycyclic aromatic compounds (PAC) has long been identified as of considerable environmental concern. Originating from both natural and anthropogenic sources, many PAC exhibit significant carcinogenic and mutagenic properties. Multi-dimensional chromatographic techniques which provide separation by virtue of chemical class (group-type) or by molecular mass greatly simplifies the analysis of inherently complex fuel materials. In this study, on-line LC-GC techniques in which high resolution gas chromatography (HPLC) have been investigated. Comprehensive characterisation of fuel feedstocks and post-pyrolysis and combustion products was achieved by coupling LC-GC to low resolution ion trap mass spectrometry (ITD-MS) and atomic emission detection (AED). Themore » identification of PAC in diesel and coal materials, as well as urban air and diesel exhaust particulate extracts has provided valuable insight into the source, formation and distribution of such compounds pre- and post processing.« less

Rapid comprehensive characterization of crude oils by thermogravimetry coupled to fast modulated gas chromatography-single photon ionization time-of-flight mass spectrometry.

PubMed

Wohlfahrt, S; Fischer, M; Saraji-Bozorgzad, M; Matuschek, G; Streibel, T; Post, E; Denner, T; Zimmermann, R

2013-09-01

Comprehensive multi-dimensional hyphenation of a thermogravimetry device (i.e. a thermobalance) to gas chromatography and single photon ionization-time-of-flight mass spectrometry (TG-GC×SPI-MS) has been used to investigate two crude oil samples of different geographical origin. The source of the applied vacuum ultraviolet radiation is an electron beam pumped rare gas excimer lamp (EBEL). The soft photoionization favors the formation of molecular ions. Introduction of a fast, rapidly modulated gas chromatographic separation step in comparison with solely TG-SPI-MS enables strongly enhanced detection especially with such highly complex organic matrices as crude oil. In contrast with former TG-SPI-MS measurements, separation and identification of overlying substances is possible because of different GC retention times. The specific contribution of isobaric compounds to one mass signal is determined for alkanes, naphthalenes, alkylated benzenes, and other compounds.

Reflections on the challenges of understanding racial, cultural and sexual differences in couple relationship research

PubMed Central

Gabb, Jacqui; Singh, Reenee

2015-01-01

In the field of systemic psychotherapy there has been much recent interest in the areas of culture and reflexivity, and in working with couples. In this article we reflect on the process of conducting research in these areas. Drawing on findings from a large, national, empirical mixed-methods study on long-term relationships, we use two examples from the data to illustrate the complexity of researching across racial, cultural and sexual differences, in terms of research design and sampling, fieldwork and research practice, and making sense of multidimensional data. We point to findings that suggest that notions of coupledom are culturally constructed and thus challenge straightforward ideas of the procreative, sexually active couple dyad, separate from intergenerational extended families. The clinical significance of the findings for both lesbian, gay, bisexual or queer and culturally diverse couples and families are discussed. Practitioner points Cultural or racial matching is not a sufficient condition for engagement and empathy with couples and families. Critical reflexivity about similarity and difference is essential in cross-cultural systemic practice. ‘The couple’ and its distance from the extended family may be defined differently in different cultures. One research tool used in this project, the emotion map, appears to have utility in clinical practice with couples and families. PMID:25820766

Sustainability assessment of tertiary wastewater treatment technologies: a multi-criteria analysis.

PubMed

Plakas, K V; Georgiadis, A A; Karabelas, A J

2016-01-01

The multi-criteria analysis gives the opportunity to researchers, designers and decision-makers to examine decision options in a multi-dimensional fashion. On this basis, four tertiary wastewater treatment (WWT) technologies were assessed regarding their sustainability performance in producing recycled wastewater, considering a 'triple bottom line' approach (i.e. economic, environmental, and social). These are powdered activated carbon adsorption coupled with ultrafiltration membrane separation (PAC-UF), reverse osmosis, ozone/ultraviolet-light oxidation and heterogeneous photo-catalysis coupled with low-pressure membrane separation (photocatalytic membrane reactor, PMR). The participatory method called simple multi-attribute rating technique exploiting ranks was employed for assigning weights to selected sustainability indicators. This sustainability assessment approach resulted in the development of a composite index as a final metric, for each WWT technology evaluated. The PAC-UF technology appears to be the most appropriate technology, attaining the highest composite value regarding the sustainability performance. A scenario analysis confirmed the results of the original scenario in five out of seven cases. In parallel, the PMR was highlighted as the technology with the least variability in its performance. Nevertheless, additional actions and approaches are proposed to strengthen the objectivity of the final results.

A Multidimensional Comparison of Maritally and Sexually Dysfunctioned Couples.

ERIC Educational Resources Information Center

Berg, Phyllis; Snyder, Douglas K.

The Marital Satisfaction Inventory (MSI) is a potential instrument for differentiating couples with specific sexual distress from those with more general marital complaints. Couples (N=45) expressing primary complaints of dissatisfaction with their sexual relationship and couples (N=45) expressing primary complaints of generalized marital distress…

Decoupling Principle Analysis and Development of a Parallel Three-Dimensional Force Sensor

PubMed Central

Zhao, Yanzhi; Jiao, Leihao; Weng, Dacheng; Zhang, Dan; Zheng, Rencheng

2016-01-01

In the development of the multi-dimensional force sensor, dimension coupling is the ubiquitous factor restricting the improvement of the measurement accuracy. To effectively reduce the influence of dimension coupling on the parallel multi-dimensional force sensor, a novel parallel three-dimensional force sensor is proposed using a mechanical decoupling principle, and the influence of the friction on dimension coupling is effectively reduced by making the friction rolling instead of sliding friction. In this paper, the mathematical model is established by combining with the structure model of the parallel three-dimensional force sensor, and the modeling and analysis of mechanical decoupling are carried out. The coupling degree (ε) of the designed sensor is defined and calculated, and the calculation results show that the mechanical decoupling parallel structure of the sensor possesses good decoupling performance. A prototype of the parallel three-dimensional force sensor was developed, and FEM analysis was carried out. The load calibration and data acquisition experiment system are built, and then calibration experiments were done. According to the calibration experiments, the measurement accuracy is less than 2.86% and the coupling accuracy is less than 3.02%. The experimental results show that the sensor system possesses high measuring accuracy, which provides a basis for the applied research of the parallel multi-dimensional force sensor. PMID:27649194

Chemometric Strategies for Peak Detection and Profiling from Multidimensional Chromatography.

PubMed

Navarro-Reig, Meritxell; Bedia, Carmen; Tauler, Romà; Jaumot, Joaquim

2018-04-03

The increasing complexity of omics research has encouraged the development of new instrumental technologies able to deal with these challenging samples. In this way, the rise of multidimensional separations should be highlighted due to the massive amounts of information that provide with an enhanced analyte determination. Both proteomics and metabolomics benefit from this higher separation capacity achieved when different chromatographic dimensions are combined, either in LC or GC. However, this vast quantity of experimental information requires the application of chemometric data analysis strategies to retrieve this hidden knowledge, especially in the case of nontargeted studies. In this work, the most common chemometric tools and approaches for the analysis of this multidimensional chromatographic data are reviewed. First, different options for data preprocessing and enhancement of the instrumental signal are introduced. Next, the most used chemometric methods for the detection of chromatographic peaks and the resolution of chromatographic and spectral contributions (profiling) are presented. The description of these data analysis approaches is complemented with enlightening examples from omics fields that demonstrate the exceptional potential of the combination of multidimensional separation techniques and chemometric tools of data analysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent advances on multidimensional liquid chromatography-mass spectrometry for proteomics: from qualitative to quantitative analysis--a review.

PubMed

Wu, Qi; Yuan, Huiming; Zhang, Lihua; Zhang, Yukui

2012-06-20

With the acceleration of proteome research, increasing attention has been paid to multidimensional liquid chromatography-mass spectrometry (MDLC-MS) due to its high peak capacity and separation efficiency. Recently, many efforts have been put to improve MDLC-based strategies including "top-down" and "bottom-up" to enable highly sensitive qualitative and quantitative analysis of proteins, as well as accelerate the whole analytical procedure. Integrated platforms with combination of sample pretreatment, multidimensional separations and identification were also developed to achieve high throughput and sensitive detection of proteomes, facilitating highly accurate and reproducible quantification. This review summarized the recent advances of such techniques and their applications in qualitative and quantitative analysis of proteomes. Copyright © 2012 Elsevier B.V. All rights reserved.

The Multidimensionality of Child Poverty: Evidence from Afghanistan

ERIC Educational Resources Information Center

Trani, Jean-Francois; Biggeri, Mario; Mauro, Vincenzo

2013-01-01

This paper examines multidimensional poverty among children in Afghanistan using the Alkire-Foster method. Several previous studies have underlined the need to separate children from their adult nexus when studying poverty and treat them according to their own specificities. From the capability approach, child poverty is understood to be the lack…

Sample dimensionality: a predictor of order-disorder in component peak distribution in multidimensional separation.

PubMed

Giddings, J C

1995-05-26

While the use of multiple dimensions in separation systems can create very high peak capacities, the effectiveness of the enhanced peak capacity in resolving large numbers of components depends strongly on whether the distribution of component peaks is ordered or disordered. Peak overlap is common in disordered distributions, even with a very high peak capacity. It is therefore of great importance to understand the origin of peak order/disorder in multidimensional separations and to address the question of whether any control can be exerted over observed levels of order and disorder and thus separation efficacy. It is postulated here that the underlying difference between ordered and disordered distributions of component peaks in separation systems is related to sample complexity as measured by a newly defined parameter, the sample dimensionality s, and by the derivative dimensionality s'. It is concluded that the type and degree of order and disorder is determined by the relationship of s (or s') to the dimensionality n of the separation system employed. Thus for some relatively simple samples (defined as having small s values), increased order and a consequent enhancement of resolution can be realized by increasing n. The resolution enhancement is in addition to the normal gain in resolving power resulting from the increased peak capacity of multidimensional systems. However, for other samples (having even smaller s values), an increase in n provides no additional benefit in enhancing component separability.

Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization

PubMed Central

Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.; Agrawal, Nitin; Tang, Keqi; Smith, Richard D.

2011-01-01

A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (≤ 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersection geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ≤ 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (≥ 7.0 × 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, little sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed. PMID:21520147

Advanced Multidimensional Separations in Mass Spectrometry: Navigating the Big Data Deluge

PubMed Central

May, Jody C.; McLean, John A.

2017-01-01

Hybrid analytical instrumentation constructed around mass spectrometry (MS) are becoming preferred techniques for addressing many grand challenges in science and medicine. From the omics sciences to drug discovery and synthetic biology, multidimensional separations based on MS provide the high peak capacity and high measurement throughput necessary to obtain large-scale measurements which are used to infer systems-level information. In this review, we describe multidimensional MS configurations as technologies which are big data drivers and discuss some new and emerging strategies for mining information from large-scale datasets. A discussion is included on the information content which can be obtained from individual dimensions, as well as the unique information which can be derived by comparing different levels of data. Finally, we discuss some emerging data visualization strategies which seek to make highly dimensional datasets both accessible and comprehensible. PMID:27306312

Multidimensional Item Response Theory Models in Vocational Interest Measurement: An Illustration Using the AIST-R

ERIC Educational Resources Information Center

Wetzel, Eunike; Hell, Benedikt

2014-01-01

Vocational interest inventories are commonly analyzed using a unidimensional approach, that is, each subscale is analyzed separately. However, the theories on which these inventories are based often postulate specific relationships between the interest traits. This article presents a multidimensional approach to the analysis of vocational interest…

Testing the Twofold Multidimensionality of Academic Self-Concept: A Study with Chinese Vocational Students

ERIC Educational Resources Information Center

Yang, Lan; Arens, A. Katrin; Watkins, David A.

2016-01-01

In order to extend previous research on the twofold multidimensionality of academic self-concept (i.e. its domain-specific structure and separation into competence and affect components), the present study tests its generalisability among vocational students from mainland China. A Chinese version of self-description questionnaire I was…

Enjoying Mathematics or Feeling Competent in Mathematics? Reciprocal Effects on Mathematics Achievement and Perceived Math Effort Expenditure

ERIC Educational Resources Information Center

Pinxten, Maarten; Marsh, Herbert W.; De Fraine, Bieke; Van Den Noortgate, Wim; Van Damme, Jan

2014-01-01

Background: The multidimensionality of the academic self-concept in terms of domain specificity has been well established in previous studies, whereas its multidimensionality in terms of motivational functions (the so-called affect-competence separation) needs further examination. Aim: This study aims at exploring differential effects of enjoyment…

Observed Score and True Score Equating Procedures for Multidimensional Item Response Theory

ERIC Educational Resources Information Center

Brossman, Bradley Grant

2010-01-01

The purpose of this research was to develop observed score and true score equating procedures to be used in conjunction with the Multidimensional Item Response Theory (MIRT) framework. Currently, MIRT scale linking procedures exist to place item parameter estimates and ability estimates on the same scale after separate calibrations are conducted.…

The potential of organic (electrospray- and atmospheric pressure chemical ionisation) mass spectrometric techniques coupled to liquid-phase separation for speciation analysis.

PubMed

Rosenberg, Erwin

2003-06-06

The use of mass spectrometry based on atmospheric pressure ionisation techniques (atmospheric pressure chemical ionisation, APCI, and electrospray ionisation, ESI) for speciation analysis is reviewed with emphasis on the literature published in and after 1999. This report accounts for the increasing interest that atmospheric pressure ionisation techniques, and in particular ESI, have found in the past years for qualitative and quantitative speciation analysis. In contrast to element-selective detectors, organic mass spectrometric techniques provide information on the intact metal species which can be used for the identification of unknown species (particularly with MS-MS detection) or the confirmation of the actual presence of species in a given sample. Due to the complexity of real samples, it is inevitable in all but the simplest cases to couple atmospheric pressure MS detection to a separation technique. Separation in the liquid phase (capillary electrophoresis or liquid chromatography in reversed phase, ion chromatographic or size-exclusion mode) is particularly suitable since the available techniques cover a very wide range of analyte polarities and molecular mass. Moreover, derivatisation can normally be avoided in liquid-phase separation. Particularly in complex environmental or biological samples, separation in one dimension is not sufficient for obtaining adequate resolution for all relevant species. In this case, multi-dimensional separation, based on orthogonal separation techniques, has proven successful. ESI-MS is also often used in parallel with inductively coupled plasma MS detection. This review is structured in two parts. In the first, the fundamentals of atmospheric pressure ionisation techniques are briefly reviewed. The second part of the review discusses recent applications including redox species, use of ESI-MS for structural elucidation of metal complexes, characterisation and quantification of small organometallic species with relevance to environment, health and food. Particular attention is given to the characterisation of biomolecules and metalloproteins (metallothioneins and phytochelatins) and to the investigation of the interaction of metals and biomolecules. Particularly in the latter field, ESI-MS is the ideal technique due to the softness of the ionisation process which allows to assume that the detected gas-phase ions are a true representation of the ions or ion-biomolecule complexes prevalent in solution. It is particularly this field, important to biochemistry, physiology and medical chemistry, where we can expect significant developments also in the future.

Multidimensional Recurrence Quantification Analysis (MdRQA) for the Analysis of Multidimensional Time-Series: A Software Implementation in MATLAB and Its Application to Group-Level Data in Joint Action

PubMed Central

Wallot, Sebastian; Roepstorff, Andreas; Mønster, Dan

2016-01-01

We introduce Multidimensional Recurrence Quantification Analysis (MdRQA) as a tool to analyze multidimensional time-series data. We show how MdRQA can be used to capture the dynamics of high-dimensional signals, and how MdRQA can be used to assess coupling between two or more variables. In particular, we describe applications of the method in research on joint and collective action, as it provides a coherent analysis framework to systematically investigate dynamics at different group levels—from individual dynamics, to dyadic dynamics, up to global group-level of arbitrary size. The Appendix in Supplementary Material contains a software implementation in MATLAB to calculate MdRQA measures. PMID:27920748

Multidimensional Recurrence Quantification Analysis (MdRQA) for the Analysis of Multidimensional Time-Series: A Software Implementation in MATLAB and Its Application to Group-Level Data in Joint Action.

PubMed

Wallot, Sebastian; Roepstorff, Andreas; Mønster, Dan

2016-01-01

We introduce Multidimensional Recurrence Quantification Analysis (MdRQA) as a tool to analyze multidimensional time-series data. We show how MdRQA can be used to capture the dynamics of high-dimensional signals, and how MdRQA can be used to assess coupling between two or more variables. In particular, we describe applications of the method in research on joint and collective action, as it provides a coherent analysis framework to systematically investigate dynamics at different group levels-from individual dynamics, to dyadic dynamics, up to global group-level of arbitrary size. The Appendix in Supplementary Material contains a software implementation in MATLAB to calculate MdRQA measures.

Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.

2011-04-26

A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (≤ 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersectionmore » geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ≤ 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (≥ 7.0 × 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, no sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed.« less

Diagnostic Efficiency of the Child and Parent Versions of the Multidimensional Anxiety Scale for Children

ERIC Educational Resources Information Center

Villabo, Marianne; Gere, Martina; Torgersen, Svenn; March, John S.; Kendall, Philip C.

2012-01-01

The objective of this study is to evaluate the psychometrics and clinical efficiency of the Multidimensional Anxiety Scale for Children (MASC), which measures physical symptoms, harm avoidance, social anxiety, and separation/panic. Using a sample of 190 treatment-seeking Norwegian youth (aged 7-13 years, M[subscript age] = 10.3 years, 62.1% male),…

Multidimensional NMR inversion without Kronecker products: Multilinear inversion

NASA Astrophysics Data System (ADS)

Medellín, David; Ravi, Vivek R.; Torres-Verdín, Carlos

2016-08-01

Multidimensional NMR inversion using Kronecker products poses several challenges. First, kernel compression is only possible when the kernel matrices are separable, and in recent years, there has been an increasing interest in NMR sequences with non-separable kernels. Second, in three or more dimensions, the singular value decomposition is not unique; therefore kernel compression is not well-defined for higher dimensions. Without kernel compression, the Kronecker product yields matrices that require large amounts of memory, making the inversion intractable for personal computers. Finally, incorporating arbitrary regularization terms is not possible using the Lawson-Hanson (LH) or the Butler-Reeds-Dawson (BRD) algorithms. We develop a minimization-based inversion method that circumvents the above problems by using multilinear forms to perform multidimensional NMR inversion without using kernel compression or Kronecker products. The new method is memory efficient, requiring less than 0.1% of the memory required by the LH or BRD methods. It can also be extended to arbitrary dimensions and adapted to include non-separable kernels, linear constraints, and arbitrary regularization terms. Additionally, it is easy to implement because only a cost function and its first derivative are required to perform the inversion.

Two multidimensional chromatographic methods for enantiomeric analysis of o,p'-DDT and o,p'-DDD in contaminated soil and air in a malaria area of South Africa.

PubMed

Naudé, Yvette; Rohwer, Egmont R

2012-06-12

In rural parts of South Africa the organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control where traditional dwellings are sprayed on the inside with small quantities of technical DDT. Since o,p'-DDT may show enantioselective oestrogenicity and biodegradability, it is important to analyse enantiomers of o,p'-DDT and its chiral degradation product, o,p'-DDD, for both health and environmental-forensic considerations. Generally, chiral analysis is performed using heart-cut multidimensional gas chromatography (MDGC) and, more recently, comprehensive two-dimensional gas chromatography (GC×GC). We developed an off-line gas chromatographic fraction collection (heart-cut) procedure for the selective capturing of the appropriate isomers from a first apolar column, followed by reinjection and separation on a second chiral column. Only the o,p'-isomers of DDT and DDD fractions from the first dimension complex chromatogram (achiral apolar GC column separation) were selectively collected onto a polydimethylsiloxane (PDMS) multichannel open tubular silicone rubber trap by simply placing the latter device on the flame tip of an inactivated flame ionisation detector (FID). The multichannel trap containing the o,p'-heart-cuts was then thermally desorbed into a GC with time-of-flight mass spectrometry detection (GC-TOFMS) for second dimension enantioselective separation on a chiral column (β-cyclodextrin-based). By selectively capturing only the o,p'-isomers from the complex sample chromatogram, (1)D separation of ultra-trace level enantiomers could be achieved on the second chiral column without matrix interference. Here, we present solventless concentration techniques for extraction of DDT from contaminated soil and air, and report enantiomeric fraction (EF) values of o,p'-DDT and o,p'-DDD obtained by a new multidimensional approach for heart-cut gas chromatographic fraction collection for off-line second dimension enantiomeric separation by (1)D GC-TOFMS of selected isomers. This multidimensional method is compared to the complementary technique of comprehensive GC×GC-TOFMS using the same enantioselective column, this time as the first dimension of separation. Copyright © 2012 Elsevier B.V. All rights reserved.

A Modified MuDPIT Separation Identified 4,488 Proteins in a System Wide Analysis of Quiescence in Yeast

PubMed Central

Webb, Kristofor J.; Xu, Tao; Park, Sung Kyu; Yates, John R.

2013-01-01

A modified multidimensional protein identification technology (MudPIT) separation was coupled to an LTQ Orbitrap Velos mass spectrometer and used to rapidly identify the near complete yeast proteome from a whole cell tryptic digest. This modified on-line two dimensional liquid chromatography separation consists of 39 strong cation exchange steps followed by a short 18.5 min reversed-phase (RP) gradient. A total of 4,269 protein identifications were made from 4,189 distinguishable protein families from yeast during log phase growth. The “Micro” MudPIT separation performed as well as a standard MudPIT separation in 40% less gradient time. The majority of the yeast proteome can now be routinely covered in less than a days’ time with high reproducibility and sensitivity. The newly devised separation method was used to detect changes in protein expression during cellular quiescence in yeast. An enrichment in the GO annotations ‘oxidation reduction’, ‘catabolic processing’ and ‘cellular response to oxidative stress’ was seen in the quiescent cellular fraction, consistent with their long lived stress resistant phenotypes. Heterogeneity was observed in the stationary phase fraction with a less dense cell population showing reductions in KEGG pathway categories of ‘Ribosome’ and ‘Proteasome’, further defining the complex nature of yeast populations present during stationary phase growth. In total 4,488 distinguishable protein families were identified in all cellular conditions tested. PMID:23540446

Biocomplexity in coupled natural–human systems: a multidimensional framework

Treesearch

S.T.A. Pickett; M.L. Cadenasso; J.M. Grove

2005-01-01

As defined by Ascher, biocomplexity results from a "multiplicity of interconnected relationships and levels. "However, no integrative framework yet exists to facilitate the application of this concept to coupled human-natural systems. Indeed, the term "biocomplexity" is still used primarily as a creative and provocative metaphor. To help advance its...

Clinical Use of the Marital Satisfaction Inventory: Two Case Studies.

ERIC Educational Resources Information Center

Wills, Robert M.; Snyder, Douglas K.

1982-01-01

Describes the clinical use of the Marital Satisfaction Inventory (MSI), a multidimensional self-report measure of marital interaction. Two case studies of couples in marital therapy are presented. The MSI is presented as a cost-efficient procedure, permitting objective assessment across multiple areas of a couple's relationship. (Author/JAC)

Chromatographic peak deconvolution of constitutional isomers by multiple-reaction-monitoring mass spectrometry.

PubMed

Trapp, Oliver

2010-02-12

Highly efficient and sophisticated separation techniques are available to analyze complex compound mixtures with superior sensitivities and selectivities often enhanced by a 2nd dimension, e.g. a separation technique or spectroscopic and spectrometric techniques. For enantioselective separations numerous chiral stationary phases (CSPs) exist to cover a broad range of chiral compounds. Despite these advances enantioselective separations can become very challenging for mixtures of stereolabile constitutional isomers, because the on-column interconversion can lead to completely overlapping peak profiles. Typically, multidimensional separation techniques, e.g. multidimensional GC (MDGC), using an achiral 1st separation dimension and transferring selected analytes to a chiral 2nd separation are the method of choice to approach such problems. However, this procedure is very time consuming and only predefined sections of peaks can be transferred by column switching to the second dimension. Here we demonstrate for stereolabile 1,2-dialkylated diaziridines a technique to experimentally deconvolute overlapping gas chromatographic elution profiles of constitutional isomers based on multiple-reaction-monitoring MS (MRM-MS). The here presented technique takes advantage of different fragmentation probabilities and pathways to isolate the elution profile of configurational isomers. Copyright 2009 Elsevier B.V. All rights reserved.

The Cognitive Visualization System with the Dynamic Projection of Multidimensional Data

NASA Astrophysics Data System (ADS)

Gorohov, V.; Vitkovskiy, V.

2008-08-01

The phenomenon of cognitive machine drawing consists in the generation on the screen the special graphic representations, which create in the brain of human operator entertainment means. These means seem man by aesthetically attractive and, thus, they stimulate its descriptive imagination, closely related to the intuitive mechanisms of thinking. The essence of cognitive effect lies in the fact that man receives the moving projection as pseudo-three-dimensional object characterizing multidimensional means in the multidimensional space. After the thorough qualitative study of the visual aspects of multidimensional means with the aid of the enumerated algorithms appears the possibility, using algorithms of standard machine drawing to paint the interesting user separate objects or the groups of objects. Then it is possible to again return to the dynamic behavior of the rotation of means for the purpose of checking the intuitive ideas of user about the clusters and the connections in multidimensional data. Is possible the development of the methods of cognitive machine drawing in combination with other information technologies, first of all with the packets of digital processing of images and multidimensional statistical analysis.

Simultaneous determination of α-asarone and β-asarone in Acorus tatarinowii using excitation-emission matrix fluorescence coupled with chemometrics methods

NASA Astrophysics Data System (ADS)

Bai, Xue-Mei; Liu, Tie; Liu, De-Long; Wei, Yong-Ju

2018-02-01

A chemometrics-assisted excitation-emission matrix (EEM) fluorescence method was proposed for simultaneous determination of α-asarone and β-asarone in Acorus tatarinowii. Using the strategy of combining EEM data with chemometrics methods, the simultaneous determination of α-asarone and β-asarone in the complex Traditional Chinese medicine system was achieved successfully, even in the presence of unexpected interferents. The physical or chemical separation step was avoided due to the use of ;mathematical separation;. Six second-order calibration methods were used including parallel factor analysis (PARAFAC), alternating trilinear decomposition (ATLD), alternating penalty trilinear decomposition (APTLD), self-weighted alternating trilinear decomposition (SWATLD), the unfolded partial least-squares (U-PLS) and multidimensional partial least-squares (N-PLS) with residual bilinearization (RBL). In addition, HPLC method was developed to further validate the presented strategy. Consequently, for the validation samples, the analytical results obtained by six second-order calibration methods were almost accurate. But for the Acorus tatarinowii samples, the results indicated a slightly better predictive ability of N-PLS/RBL procedure over other methods.

Identification of aroma-active volatiles in banana Terra spirit using multidimensional gas chromatography with simultaneous mass spectrometry and olfactometry detection.

PubMed

Capobiango, Michely; Mastello, Raíssa Bittar; Chin, Sung-Tong; Oliveira, Evelyn de Souza; Cardeal, Zenilda de Lourdes; Marriott, Philip John

2015-04-03

Fruit spirits have been produced and consumed throughout the world for centuries. However, the aroma composition of banana spirits is still poorly characterised. We have investigated the aroma-impact compounds of the banana Terra spirit for the first time, using multidimensional gas chromatography (MDGC and GC × GC) in a multi-hyphenated system - i.e., coupled to flame ionisation detection (FID), mass spectrometry (MS), and olfactometry (O). Solid-phase microextraction (SPME) was used to isolate the headspace aroma compounds of the banana spirit. The detection frequency (DF) technique was applied and aroma regions, detected in the first column separation at >60% Nasal Impact Frequency (NIF), were screened as target potent odour regions in the sample. Using a polar/non-polar phase column set, the potent odour regions were further subjected to MDGC separation with simultaneous O and MS detection for correlation of the aroma perception with MS data for individual resolved aroma-impact compounds. GC-O analysis enabled 18 aroma-impact regions to be located as providing volatiles of interest for further study; for example, those comprising perceptions of flower, whisky, green, amongst others. Compounds were tentatively identified through MS data matching and retention indices in both first and second dimensions. The principal volatile compounds identified in this work, which are responsible for the characteristic aroma of the banana spirit, are 3-methylbutan-1-ol, 3-methylbutan-1-ol acetate, 2-phenylethyl acetate and phenylethyl alcohol. This is the first such study to reveal the major aroma compounds that contribute to banana spirit aroma. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessing Anxiety in Youth with the Multidimensional Anxiety Scale for Children (MASC)

PubMed Central

Wei, Chiaying; Hoff, Alexandra; Villabø, Marianne A.; Peterman, Jeremy; Kendall, Philip C.; Piacentini, John; McCracken, James; Walkup, John T.; Albano, Anne Marie; Rynn, Moira; Sherrill, Joel; Sakolsky, Dara; Birmaher, Boris; Ginsburg, Golda; Keaton, Courtney; Gosch, Elizabeth; Compton, Scott N.; March, John

2013-01-01

The present study examined the psychometric properties, including discriminant validity and clinical utility, of the youth self-report and parent-report forms of the Multidimensional Anxiety Scale for Children (MASC) among youth with anxiety disorders. The sample included parents and youth (N= 488, 49.6% male) ages 7 – 17 who participated in the Child/Adolescent Anxiety Multimodal Study (CAMS). Although the typical low agreement between parent and youth self-reports was found, the MASC evidenced good internal reliability across MASC subscales and informants. The main MASC subscales (i.e., Physical Symptoms, Harm Avoidance, Social Anxiety, and Separation/Panic) were examined. The Social Anxiety and Separation/Panic subscales were found to be significantly predictive of the presence and severity of social phobia and separation anxiety disorder, respectively. Using multiple informants improved the accuracy of prediction. The MASC subscales demonstrated good psychometric properties and clinical utilities in identifying youth with anxiety disorders. PMID:23845036

Hospital Social Workers and Indirect Trauma Exposure: An Exploratory Study of Contributing Factors

ERIC Educational Resources Information Center

Badger, Karen; Royse, David; Craig, Carlton

2008-01-01

This article explores the predictive ability of empathy (measured by the Interpersonal Reactivity Index), emotional separation (measured by the Maintenance of Emotional Separation Scale), occupational stress (measured by the Work-Related Strain Inventory), and social support (measured by the Multidimensional Scale of Perceived Social Support) on…

Cumulative area of peaks in a multidimensional high performance liquid chromatogram.

PubMed

Stevenson, Paul G; Guiochon, Georges

2013-09-20

An algorithm was developed to recognize peaks in a multidimensional separation and calculate their cumulative peak area. To find the retention times of peaks in a one dimensional chromatogram, the Savitzky-Golay smoothing filter was used to smooth and find the first through third derivatives of the experimental profiles. Close examination of the shape of these curves informs on the number of peaks that are present and provides starting values for fitting theoretical profiles. Due to the nature of comprehensive multidimensional HPLC, adjacent cut fractions may contain compounds common to more than one cut fraction. The algorithm determines which components were common in adjacent cuts and subsequently calculates the area of a two-dimensional peak profile by interpolating the surface of the 2D peaks between adjacent peaks. This algorithm was tested by calculating the cumulative peak area of a series of 2D-HPLC separations of alkylbenzenes, phenol and caffeine with varied concentrations. A good relationship was found between the concentration and the cumulative peak area. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of comprehensive multidimensional gas chromatography combined with time-of-flight mass spectrometry (GC x GC-TOFMS) for high resolution analysis of hop essential oil.

PubMed

Roberts, Mark T; Dufour, Jean-Pierre; Lewis, Alastair C

2004-04-01

The selection and quality of hops is a major determinant in beer flavour. Brewers acknowledge that distinctive characteristics of different hop varieties can be traced to the composition of their essential oils. The difficulty in characterising complex mixtures such as hop oil using 1-D chromatography is that many compounds co-elute. With the introduction of comprehensive multidimensional capillary gas chromatography (GC x GC), there is a tremendous improvement in the separation power or peak capacity. Recent work using GC x GC with flame ionisation detection has suggested that there may be over 1,000 compounds in hop oil. This work describes the use of GC x GC combined with TOFMS detection (Leco Pegasus 4D instrument) to analyse Target hop oil. The TOFMS spectral acquisition rate of 60 Hz provided sufficient spectra per peak (2-D peak base width of 0.1-0.2 s) for identification (119 components were identified with 45 previously unreported compounds). When analysing results, an advantage of GC x GC coupled to TOFMS is that 2-D chromatograms can be viewed for individual masses that are characteristic of particular functional groups. This allows the analyst to view the various homologous series of compounds although in certain cases coelution may still be present as shown by the esters with mass 75.

Surface modified capillary electrophoresis combined with in solution isoelectric focusing and MALDI-TOF/TOF MS: a gel-free multidimensional electrophoresis approach for proteomic profiling--exemplified on human follicular fluid.

PubMed

Hanrieder, Jörg; Zuberovic, Aida; Bergquist, Jonas

2009-04-24

Development of miniaturized analytical tools continues to be of great interest to face the challenges in proteomic analysis of complex biological samples such as human body fluids. In the light of these challenges, special emphasis is put on the speed and simplicity of newly designed technological approaches as well as the need for cost efficiency and low sample consumption. In this study, we present an alternative multidimensional bottom-up approach for proteomic profiling for fast, efficient and sensitive protein analysis in complex biological matrices. The presented setup was based on sample pre-fractionation using microscale in solution isoelectric focusing (IEF) followed by tryptic digestion and subsequent capillary electrophoresis (CE) coupled off-line to matrix assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI TOF MS/MS). For high performance CE-separation, PolyE-323 modified capillaries were applied to minimize analyte-wall interactions. The potential of the analytical setup was demonstrated on human follicular fluid (hFF) representing a typical complex human body fluid with clinical implication. The obtained results show significant identification of 73 unique proteins (identified at 95% significance level), including mostly acute phase proteins but also protein identities that are well known to be extensively involved in follicular development.

Dimension reduction for stochastic dynamical systems forced onto a manifold by large drift: a constructive approach with examples from theoretical biology

NASA Astrophysics Data System (ADS)

Parsons, Todd L.; Rogers, Tim

2017-10-01

Systems composed of large numbers of interacting agents often admit an effective coarse-grained description in terms of a multidimensional stochastic dynamical system, driven by small-amplitude intrinsic noise. In applications to biological, ecological, chemical and social dynamics it is common for these models to posses quantities that are approximately conserved on short timescales, in which case system trajectories are observed to remain close to some lower-dimensional subspace. Here, we derive explicit and general formulae for a reduced-dimension description of such processes that is exact in the limit of small noise and well-separated slow and fast dynamics. The Michaelis-Menten law of enzyme-catalysed reactions, and the link between the Lotka-Volterra and Wright-Fisher processes are explored as a simple worked examples. Extensions of the method are presented for infinite dimensional systems and processes coupled to non-Gaussian noise sources.

Testing Separability and Independence of Perceptual Dimensions with General Recognition Theory: A Tutorial and New R Package (grtools).

PubMed

Soto, Fabian A; Zheng, Emily; Fonseca, Johnny; Ashby, F Gregory

2017-01-01

Determining whether perceptual properties are processed independently is an important goal in perceptual science, and tools to test independence should be widely available to experimental researchers. The best analytical tools to test for perceptual independence are provided by General Recognition Theory (GRT), a multidimensional extension of signal detection theory. Unfortunately, there is currently a lack of software implementing GRT analyses that is ready-to-use by experimental psychologists and neuroscientists with little training in computational modeling. This paper presents grtools , an R package developed with the explicit aim of providing experimentalists with the ability to perform full GRT analyses using only a couple of command lines. We describe the software and provide a practical tutorial on how to perform each of the analyses available in grtools . We also provide advice to researchers on best practices for experimental design and interpretation of results when applying GRT and grtools .

A Typology of Marital Quality of Enduring Marriages in Israel

ERIC Educational Resources Information Center

Cohen, Orna; Geron, Yael; Farchi, Alva

2010-01-01

This article presents a typology of enduring marriages of Israeli couples married for at least 40 years. Based on the view that marital quality is a multidimensional phenomenon, the typology is derived from a cluster analysis of responses of husbands and wives in 51 couples to the ENRICH scale items. Three types of enduring marriages were found:…

A Novel Multi-Scale Domain Overlapping CFD/STH Coupling Methodology for Multi-Dimensional Flows Relevant to Nuclear Applications

NASA Astrophysics Data System (ADS)

Grunloh, Timothy P.

The objective of this dissertation is to develop a 3-D domain-overlapping coupling method that leverages the superior flow field resolution of the Computational Fluid Dynamics (CFD) code STAR-CCM+ and the fast execution of the System Thermal Hydraulic (STH) code TRACE to efficiently and accurately model thermal hydraulic transport properties in nuclear power plants under complex conditions of regulatory and economic importance. The primary contribution is the novel Stabilized Inertial Domain Overlapping (SIDO) coupling method, which allows for on-the-fly correction of TRACE solutions for local pressures and velocity profiles inside multi-dimensional regions based on the results of the CFD simulation. The method is found to outperform the more frequently-used domain decomposition coupling methods. An STH code such as TRACE is designed to simulate large, diverse component networks, requiring simplifications to the fluid flow equations for reasonable execution times. Empirical correlations are therefore required for many sub-grid processes. The coarse grids used by TRACE diminish sensitivity to small scale geometric details such as Reactor Pressure Vessel (RPV) internals. A CFD code such as STAR-CCM+ uses much finer computational meshes that are sensitive to the geometric details of reactor internals. In turbulent flows, it is infeasible to fully resolve the flow solution, but the correlations used to model turbulence are at a low level. The CFD code can therefore resolve smaller scale flow processes. The development of a 3-D coupling method was carried out with the intention of improving predictive capabilities of transport properties in the downcomer and lower plenum regions of an RPV in reactor safety calculations. These regions are responsible for the multi-dimensional mixing effects that determine the distribution at the core inlet of quantities with reactivity implications, such as fluid temperature and dissolved neutron absorber concentration.

Phase coupling in the cardiorespiratory interaction.

PubMed

Bahraminasab, A; Kenwright, D; Stefanovska, A; Ghasemi, F; McClintock, P V E

2008-01-01

Markovian analysis is applied to derive nonlinear stochastic equations for the reconstruction of heart rate and respiration rate variability data. A model of their 'phase' interactions is obtained for the first time, thereby gaining new insights into the strength and direction of the cardiorespiratory phase coupling. The reconstructed model can reproduce synchronisation phenomena between the cardiac and the respiratory systems, including switches in synchronisation ratio. The technique is equally applicable to the extraction of the multi-dimensional couplings between many interacting subsystems.

A Multidimensional Ideal Point Item Response Theory Model for Binary Data.

PubMed

Maydeu-Olivares, Albert; Hernández, Adolfo; McDonald, Roderick P

2006-12-01

We introduce a multidimensional item response theory (IRT) model for binary data based on a proximity response mechanism. Under the model, a respondent at the mode of the item response function (IRF) endorses the item with probability one. The mode of the IRF is the ideal point, or in the multidimensional case, an ideal hyperplane. The model yields closed form expressions for the cell probabilities. We estimate and test the goodness of fit of the model using only information contained in the univariate and bivariate moments of the data. Also, we pit the new model against the multidimensional normal ogive model estimated using NOHARM in four applications involving (a) attitudes toward censorship, (b) satisfaction with life, (c) attitudes of morality and equality, and (d) political efficacy. The normal PDF model is not invariant to simple operations such as reverse scoring. Thus, when there is no natural category to be modeled, as in many personality applications, it should be fit separately with and without reverse scoring for comparisons.

Multidimensional Mixing Behavior of Steam-Water Flow in a Downcomer Annulus During LBLOCA Reflood Phase with a Direct Vessel Injection Mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, Tae-Soon; Yun, Byong-Jo; Euh, Dong-Jin

Multidimensional thermal-hydraulic behavior in the downcomer annulus of a pressurized water reactor (PWR) vessel with a direct vessel injection mode is presented based on the experimental observation in the MIDAS (multidimensional investigation in downcomer annulus simulation) steam-water test facility. From the steady-state test results to simulate the late reflood phase of a large-break loss-of-coolant accident (LBLOCA), isothermal lines show the multidimensional phenomena of a phasic interaction between steam and water in the downcomer annulus very well. MIDAS is a steam-water separate effect test facility, which is 1/4.93 linearly scaled down to a 1400-MW(electric) PWR type of a nuclear reactor, focusedmore » on understanding multidimensional thermal-hydraulic phenomena in a downcomer annulus with various types of safety injection during the refill or reflood phase of an LBLOCA. The initial and the boundary conditions are scaled from the pretest analysis based on the preliminary calculation using the TRAC code. The superheated steam with a superheating degree of 80 K at a given downcomer pressure of 180 kPa is injected equally through three intact cold legs into the downcomer.« less

Upscaling the Coupled Water and Heat Transport in the Shallow Subsurface

NASA Astrophysics Data System (ADS)

Sviercoski, R. F.; Efendiev, Y.; Mohanty, B. P.

2018-02-01

Predicting simultaneous movement of liquid water, water vapor, and heat in the shallow subsurface has many practical interests. The demand for multidimensional multiscale models for this region is important given: (a) the critical role that these processes play in the global water and energy balances, (b) that more data from air-borne and space-borne sensors are becoming available for parameterizations of modeling efforts. On the other hand, numerical models that consider spatial variations of the soil properties, termed here as multiscale, are prohibitively expensive. Thus, there is a need for upscaled models that take into consideration these features, and be computationally affordable. In this paper, a multidimensional multiscale model coupling the water flow and heat transfer and its respective upscaled version are proposed. The formulation is novel as it describes the multidimensional and multiscale tensorial versions of the hydraulic conductivity and the vapor diffusivity, taking into account the tortuosity and porosity properties of the medium. It also includes the coupling with the energy balance equation as a boundary describing atmospheric influences at the shallow subsurface. To demonstrate the accuracy of both models, comparisons were made between simulation and field experiments for soil moisture and temperature at 2, 7, and 12 cm deep, during 11 days. The root-mean-square errors showed that the upscaled version of the system captured the multiscale features with similar accuracy. Given the good matching between simulated and field data for near-surface soil temperature, the results suggest that it can be regarded as a 1-D variable.

LC-IMS-MS Feature Finder. Detecting Multidimensional Liquid Chromatography, Ion Mobility, and Mass Spectrometry Features in Complex Datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowell, Kevin L.; Slysz, Gordon W.; Baker, Erin Shammel

2013-09-05

We introduce a command line software application LC-IMS-MS Feature Finder that searches for molecular ion signatures in multidimensional liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) data by clustering deisotoped peaks with similar monoisotopic mass, charge state, LC elution time, and ion mobility drift time values. The software application includes an algorithm for detecting and quantifying co-eluting chemical species, including species that exist in multiple conformations that may have been separated in the IMS dimension.

Molecular Dynamics Simulations and Classical Multidimensional Scaling Unveil New Metastable States in the Conformational Landscape of CDK2

PubMed Central

Pisani, Pasquale; Rastelli, Giulio

2016-01-01

Protein kinases are key regulatory nodes in cellular networks and their function has been shown to be intimately coupled with their structural flexibility. However, understanding the key structural mechanisms of large conformational transitions remains a difficult task. CDK2 is a crucial regulator of cell cycle. Its activity is finely tuned by Cyclin E/A and the catalytic segment phosphorylation, whereas its deregulation occurs in many types of cancer. ATP competitive inhibitors have failed to be approved for clinical use due to toxicity issues raised by a lack of selectivity. However, in the last few years type III allosteric inhibitors have emerged as an alternative strategy to selectively modulate CDK2 activity. In this study we have investigated the conformational variability of CDK2. A low dimensional conformational landscape of CDK2 was modeled using classical multidimensional scaling on a set of 255 crystal structures. Microsecond-scale plain and accelerated MD simulations were used to populate this landscape by using an out-of-sample extension of multidimensional scaling. CDK2 was simulated in the apo-form and in complex with the allosteric inhibitor 8-anilino-1-napthalenesulfonic acid (ANS). The apo-CDK2 landscape analysis showed a conformational equilibrium between an Src-like inactive conformation and an active-like form. These two states are separated by different metastable states that share hybrid structural features with both forms of the kinase. In contrast, the CDK2/ANS complex landscape is compatible with a conformational selection picture where the binding of ANS in proximity of the αC helix causes a population shift toward the inactive conformation. Interestingly, the new metastable states could enlarge the pool of candidate structures for the development of selective allosteric CDK2 inhibitors. The method here presented should not be limited to the CDK2 case but could be used to systematically unmask similar mechanisms throughout the human kinome. PMID:27100206

Molecular Dynamics Simulations and Classical Multidimensional Scaling Unveil New Metastable States in the Conformational Landscape of CDK2.

PubMed

Pisani, Pasquale; Caporuscio, Fabiana; Carlino, Luca; Rastelli, Giulio

2016-01-01

Protein kinases are key regulatory nodes in cellular networks and their function has been shown to be intimately coupled with their structural flexibility. However, understanding the key structural mechanisms of large conformational transitions remains a difficult task. CDK2 is a crucial regulator of cell cycle. Its activity is finely tuned by Cyclin E/A and the catalytic segment phosphorylation, whereas its deregulation occurs in many types of cancer. ATP competitive inhibitors have failed to be approved for clinical use due to toxicity issues raised by a lack of selectivity. However, in the last few years type III allosteric inhibitors have emerged as an alternative strategy to selectively modulate CDK2 activity. In this study we have investigated the conformational variability of CDK2. A low dimensional conformational landscape of CDK2 was modeled using classical multidimensional scaling on a set of 255 crystal structures. Microsecond-scale plain and accelerated MD simulations were used to populate this landscape by using an out-of-sample extension of multidimensional scaling. CDK2 was simulated in the apo-form and in complex with the allosteric inhibitor 8-anilino-1-napthalenesulfonic acid (ANS). The apo-CDK2 landscape analysis showed a conformational equilibrium between an Src-like inactive conformation and an active-like form. These two states are separated by different metastable states that share hybrid structural features with both forms of the kinase. In contrast, the CDK2/ANS complex landscape is compatible with a conformational selection picture where the binding of ANS in proximity of the αC helix causes a population shift toward the inactive conformation. Interestingly, the new metastable states could enlarge the pool of candidate structures for the development of selective allosteric CDK2 inhibitors. The method here presented should not be limited to the CDK2 case but could be used to systematically unmask similar mechanisms throughout the human kinome.

Analysis of the time structure of synchronization in multidimensional chaotic systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makarenko, A. V., E-mail: avm.science@mail.ru

2015-05-15

A new approach is proposed to the integrated analysis of the time structure of synchronization of multidimensional chaotic systems. The method allows one to diagnose and quantitatively evaluate the intermittency characteristics during synchronization of chaotic oscillations in the T-synchronization mode. A system of two identical logistic mappings with unidirectional coupling that operate in the developed chaos regime is analyzed. It is shown that the widely used approach, in which only synchronization patterns are subjected to analysis while desynchronization areas are considered as a background signal and removed from analysis, should be regarded as methodologically incomplete.

Multi-dimensional scores to predict mortality in patients with idiopathic pulmonary fibrosis undergoing lung transplantation assessment.

PubMed

Fisher, Jolene H; Al-Hejaili, Faris; Kandel, Sonja; Hirji, Alim; Shapera, Shane; Mura, Marco

2017-04-01

The heterogeneous progression of idiopathic pulmonary fibrosis (IPF) makes prognostication difficult and contributes to high mortality on the waitlist for lung transplantation (LTx). Multi-dimensional scores (Composite Physiologic index [CPI], [Gender-Age-Physiology [GAP]; RIsk Stratification scorE [RISE]) demonstrated enhanced predictive power towards outcome in IPF. The lung allocation score (LAS) is a multi-dimensional tool commonly used to stratify patients assessed for LTx. We sought to investigate whether IPF-specific multi-dimensional scores predict mortality in patients with IPF assessed for LTx. The study included 302 patients with IPF who underwent a LTx assessment (2003-2014). Multi-dimensional scores were calculated. The primary outcome was 12-month mortality after assessment. LTx was considered as competing event in all analyses. At the end of the observation period, there were 134 transplants, 63 deaths, and 105 patients were alive without LTx. Multi-dimensional scores predicted mortality with accuracy similar to LAS, and superior to that of individual variables: area under the curve (AUC) for LAS was 0.78 (sensitivity 71%, specificity 86%); CPI 0.75 (sensitivity 67%, specificity 82%); GAP 0.67 (sensitivity 59%, specificity 74%); RISE 0.78 (sensitivity 71%, specificity 84%). A separate analysis conducted only in patients actively listed for LTx (n = 247; 50 deaths) yielded similar results. In patients with IPF assessed for LTx as well as in those actually listed, multi-dimensional scores predict mortality better than individual variables, and with accuracy similar to the LAS. If validated, multi-dimensional scores may serve as inexpensive tools to guide decisions on the timing of referral and listing for LTx. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantitative evaluation of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Duchesne, S.; Frisoni, G. B.

2009-02-01

We propose a single, quantitative metric called the disease evaluation factor (DEF) and assess its efficiency at estimating disease burden in normal, control subjects (CTRL) and probable Alzheimer's disease (AD) patients. The study group consisted in 75 patients with a diagnosis of probable AD and 75 age-matched normal CTRL without neurological or neuropsychological deficit. We calculated a reference eigenspace of MRI appearance from reference data, in which our CTRL and probable AD subjects were projected. We then calculated the multi-dimensional hyperplane separating the CTRL and probable AD groups. The DEF was estimated via a multidimensional weighted distance of eigencoordinates for a given subject and the CTRL group mean, along salient principal components forming the separating hyperplane. We used quantile plots, Kolmogorov-Smirnov and χ2 tests to compare the DEF values and test that their distribution was normal. We used a linear discriminant test to separate CTRL from probable AD based on the DEF factor, and reached an accuracy of 87%. A quantitative biomarker in AD would act as an important surrogate marker of disease status and progression.

From Molecules to Cells to Organisms: Understanding Health and Disease with Multidimensional Single-Cell Methods

NASA Astrophysics Data System (ADS)

Candia, Julián

2013-03-01

The multidimensional nature of many single-cell measurements (e.g. multiple markers measured simultaneously using Fluorescence-Activated Cell Sorting (FACS) technologies) offers unprecedented opportunities to unravel emergent phenomena that are governed by the cooperative action of multiple elements across different scales, from molecules and proteins to cells and organisms. We will discuss an integrated analysis framework to investigate multicolor FACS data from different perspectives: Singular Value Decomposition to achieve an effective dimensional reduction in the data representation, machine learning techniques to separate different patient classes and improve diagnosis, as well as a novel cell-similarity network analysis method to identify cell subpopulations in an unbiased manner. Besides FACS data, this framework is versatile: in this vein, we will demonstrate an application to the multidimensional single-cell shape analysis of healthy and prematurely aged cells.

An efficient multi-dimensional implementation of VSIAM3 and its applications to free surface flows

NASA Astrophysics Data System (ADS)

Yokoi, Kensuke; Furuichi, Mikito; Sakai, Mikio

2017-12-01

We propose an efficient multidimensional implementation of VSIAM3 (volume/surface integrated average-based multi-moment method). Although VSIAM3 is a highly capable fluid solver based on a multi-moment concept and has been used for a wide variety of fluid problems, VSIAM3 could not simulate some simple benchmark problems well (for instance, lid-driven cavity flows) due to relatively high numerical viscosity. In this paper, we resolve the issue by using the efficient multidimensional approach. The proposed VSIAM3 is shown to capture lid-driven cavity flows of the Reynolds number up to Re = 7500 with a Cartesian grid of 128 × 128, which was not capable for the original VSIAM3. We also tested the proposed framework in free surface flow problems (droplet collision and separation of We = 40 and droplet splashing on a superhydrophobic substrate). The numerical results by the proposed VSIAM3 showed reasonable agreements with these experiments. The proposed VSIAM3 could capture droplet collision and separation of We = 40 with a low numerical resolution (8 meshes for the initial diameter of droplets). We also simulated free surface flows including particles toward non-Newtonian flow applications. These numerical results have showed that the proposed VSIAM3 can robustly simulate interactions among air, particles (solid), and liquid.

Multidimensional and comprehensive two-dimensional gas chromatography of dichloromethane soluble products from a high sulfur Jordanian oil shale.

PubMed

Amer, Mohammad W; Mitrevski, Blagoj; Jackson, W Roy; Chaffee, Alan L; Marriott, Philip J

2014-03-01

A high sulfur Jordanian oil shale was converted into liquid hydrocarbons by reaction at 390 °C under N2, and the dichloromethane soluble fraction of the products was isolated then analyzed by using gas chromatography (GC). Comprehensive two-dimensional GC (GC×GC) and multidimensional GC (MDGC) were applied for component separation on a polar - non-polar column set. Flame-ionization detection (FID) was used with GC×GC for general sample profiling, and mass spectrometry (MS) for component identification in MDGC. Multidimensional GC revealed a range of thiophenes (th), benzothiophenes (bth) and small amounts of dibenzothiophenes (dbth) and benzonaphthothiophenes (bnth). In addition, a range of aliphatic alkanes and cycloalkanes, ethers, polar single ring aromatic compounds and small amounts of polycyclic aromatics were also identified. Some of these compound classes were not uniquely observable by conventional 1D GC, and certainly this is true for many of their minor constituent members. The total number of distinct compounds was very large (ca.>1000). GC×GC was shown to be appropriate for general sample profiling, and MDGC-MS proved to be a powerful technique for the separation and identification of sulfur-containing components and other polar compounds. © 2013 Published by Elsevier B.V.

Kinetic Modeling of Slow Energy Release in Non-Ideal Carbon Rich Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitello, P; Fried, L; Glaesemann, K

2006-06-20

We present here the first self-consistent kinetic based model for long time-scale energy release in detonation waves in the non-ideal explosive LX-17. Non-ideal, insensitive carbon rich explosives, such as those based on TATB, are believed to have significant late-time slow release in energy. One proposed source of this energy is diffusion-limited growth of carbon clusters. In this paper we consider the late-time energy release problem in detonation waves using the thermochemical code CHEETAH linked to a multidimensional ALE hydrodynamics model. The linked CHEETAH-ALE model dimensional treats slowly reacting chemical species using kinetic rate laws, with chemical equilibrium assumed for speciesmore » coupled via fast time-scale reactions. In the model presented here we include separate rate equations for the transformation of the un-reacted explosive to product gases and for the growth of a small particulate form of condensed graphite to a large particulate form. The small particulate graphite is assumed to be in chemical equilibrium with the gaseous species allowing for coupling between the instantaneous thermodynamic state and the production of graphite clusters. For the explosive burn rate a pressure dependent rate law was used. Low pressure freezing of the gas species mass fractions was also included to account for regions where the kinetic coupling rates become longer than the hydrodynamic time-scales. The model rate parameters were calibrated using cylinder and rate-stick experimental data. Excellent long time agreement and size effect results were achieved.« less

Discriminating cascading processes in nonlinear optics: A QED analysis based on their molecular and geometric origin

NASA Astrophysics Data System (ADS)

Bennett, Kochise; Chernyak, Vladimir Y.; Mukamel, Shaul

2017-03-01

The nonlinear optical response of a system of molecules often contains contributions whereby the products of lower-order processes in two separate molecules give signals that appear on top of a genuine direct higher-order process with a single molecule. These many-body contributions are known as cascading and complicate the interpretation of multidimensional stimulated Raman and other nonlinear signals. In a quantum electrodynamic treatment, these cascading processes arise from second-order expansion in the molecular coupling to vacuum modes of the radiation field, i.e., single-photon exchange between molecules, which also gives rise to other collective effects. We predict the relative phase of the direct and cascading nonlinear signals and its dependence on the microscopic dynamics as well as the sample geometry. This phase may be used to identify experimental conditions for distinguishing the direct and cascading signals by their phase. Higher-order cascading processes involving the exchange of several photons between more than two molecules are discussed.

Integration of isoelectric focusing with parallel sodium dodecyl sulfate gel electrophoresis for multidimensional protein separations in a plastic microfluidic [correction of microfludic] network.

PubMed

Li, Yan; Buch, Jesse S; Rosenberger, Frederick; DeVoe, Don L; Lee, Cheng S

2004-02-01

An integrated protein concentration/separation system, combining non-native isoelectric focusing (IEF) with sodium dodecyl sulfate (SDS) gel electrophoresis on a polymer microfluidic chip, is reported. The system provides significant analyte concentration and extremely high resolving power for separated protein mixtures. The ability to introduce and isolate multiple separation media in a plastic microfluidic network is one of two key requirements for achieving multidimensional protein separations. The second requirement lies in the quantitative transfer of focused proteins from the first to second separation dimensions without significant loss in the resolution acquired from the first dimension. Rather than sequentially sampling protein analytes eluted from IEF, focused proteins are electrokinetically transferred into an array of orthogonal microchannels and further resolved by SDS gel electrophoresis in a parallel and high-throughput format. Resolved protein analytes are monitored using noncovalent, environment-sensitive, fluorescent probes such as Sypro Red. In comparison with covalently labeling proteins, the use of Sypro staining during electrophoretic separations not only presents a generic detection approach for the analysis of complex protein mixtures such as cell lysates but also avoids additional introduction of protein microheterogeneity as the result of labeling reaction. A comprehensive 2-D protein separation is completed in less than 10 min with an overall peak capacity of approximately 1700 using a chip with planar dimensions of as small as 2 cm x 3 cm. Significant enhancement in the peak capacity can be realized by simply raising the density of microchannels in the array, thereby increasing the number of IEF fractions further analyzed in the size-based separation dimension.

An evaluation of the effects of high visual taskload on the separate behaviors involved in complex monitoring performance.

DOT National Transportation Integrated Search

1988-01-01

Operational monitoring situations, in contrast to typical laboratory vigilance tasks, generally involve more than just stimulus detection and recognition. They frequently involve complex multidimensional discriminations, interpretations of significan...

Characterization of plant polysaccharides from Dendrobium officinale by multiple chromatographic and mass spectrometric techniques.

PubMed

Ma, Huiying; Zhang, Keke; Jiang, Qing; Dai, Diya; Li, Hongli; Bi, Wentao; Chen, David Da Yong

2018-04-27

Plant polysaccharides have numerous medicinal functions. Due to the differences in their origins, regions of production, and cultivation conditions, the quality and the functions of polysaccharides can vary significantly. They are macromolecules with large molecular weight (MW) and complex structure, and pose great challenge for the analytical technology used. Taking Dendrobium officinale (DO) from various origins and locations as model samples. In this investigation, mechanochemical extraction method was used to successfully extract polysaccharides from DO using water as solvent, the process is simple, fast (40 s) and with high yield. The MWs of the intact saccharides from calibration curve and light scattering measurement were determined and compared after separation with size exclusion chromatography (SEC). The large polysaccharide was acid hydrolyzed to oligosaccharides and the products were efficiently separated and identified using liquid chromatography coupled to a high resolution tandem mass spectrometry (LC-MS 2 ). Obvious differences were observed among LC-MS 2 chromatograms of digested products, and the chemical structures for the products were proposed based on accurate mass values. More importantly, isomeric digested carbohydrate compounds were explored and characterized. All the chromatographic and mass spectrometric results in this study provided a multi-dimensional characterization, fingerprint analysis, and molecular structure level assessment of plant polysaccharides. Copyright © 2018 Elsevier B.V. All rights reserved.

Spectral and fractal analyses of geomagnetic and riometric antarctic observations and a multidimensional index of activity

NASA Astrophysics Data System (ADS)

de Santis, A.; de Franceschi, G.; Perrone, L.

1997-06-01

The Istituto Nazionale di Geofisica under the P.N.R.A. (National Program of Research in Antarctica) has the responsibility of acquiring geophysical observations at the Italian Antarctic Base of Terra Nova Bay. Among others, geomagnetic and riometric data can provide some new insights into local and global activity of the magnetosphere-ionosphere coupling. This article investigates some properties of these kinds of data by means of spectral and fractal analyses. In addition, a multidimensional index is derived from this single-point dataset to represent not only the local but also the global state of the magnetospheric activity.

Variational transition state theory for multidimensional activated rate processes in the presence of anisotropic friction

NASA Astrophysics Data System (ADS)

Berezhkovskii, Alexander M.; Frishman, Anatoli M.; Pollak, Eli

1994-09-01

Variational transition state theory (VTST) is applied to the study of the activated escape of a particle trapped in a multidimensional potential well and coupled to a heat bath. Special attention is given to the dependence of the rate constant on the friction coefficients in the case of anisotropic friction. It is demonstrated explicitly that both the traditional as well as the nontraditional scenarios for the particle escape are recovered uniformly within the framework of VTST. Effects such as saddle point avoidance and friction dependence of the activation energy are derived from VTST using optimized planar dividing surfaces.

Numerical simulation of two-dimensional flow over a heated carbon surface with coupled heterogeneous and homogeneous reactions

NASA Astrophysics Data System (ADS)

Johnson, Ryan Federick; Chelliah, Harsha Kumar

2017-01-01

For a range of flow and chemical timescales, numerical simulations of two-dimensional laminar flow over a reacting carbon surface were performed to understand further the complex coupling between heterogeneous and homogeneous reactions. An open-source computational package (OpenFOAM®) was used with previously developed lumped heterogeneous reaction models for carbon surfaces and a detailed homogeneous reaction model for CO oxidation. The influence of finite-rate chemical kinetics was explored by varying the surface temperatures from 1800 to 2600 K, while flow residence time effects were explored by varying the free-stream velocity up to 50 m/s. The reacting boundary layer structure dependence on the residence time was analysed by extracting the ratio of chemical source and species diffusion terms. The important contributions of radical species reactions on overall carbon removal rate, which is often neglected in multi-dimensional simulations, are highlighted. The results provide a framework for future development and validation of lumped heterogeneous reaction models based on multi-dimensional reacting flow configurations.

Highly Enhanced Photoelectrochemical Water Oxidation Efficiency Based on Triadic Quantum Dot/Layered Double Hydroxide/BiVO 4 Photoanodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Yanqun; Wang, Ruirui; Yang, Ye

2016-08-03

The water oxidation half-reaction is considered to be a bottleneck for achieving highly efficient solar-driven water splitting due to its multiproton-coupled four-electron process and sluggish kinetics. Herein, a triadic photoanode consisting of dual-sized CdTe quantum dots (QDs), Co-based layered double hydroxide (LDH) nanosheets, and BiVO4 particles, that is, QD@LDH@BiVO4, was designed. Two sets of consecutive Type-II band alignments were constructed to improve photogenerated electron-hole separation in the triadic structure. The efficient charge separation resulted in a 2-fold enhancement of the photocurrent of the QD@LDH@BiVO4 photoanode. A significantly enhanced oxidation efficiency reaching above 90% in the low bias region (i.e., Emore » < 0.8 V vs RHE) could be critical in determining the overall performance of a complete photoelectrochemical cell. The faradaic efficiency for water oxidation was almost 90%. The conduction band energy of QDs is -1.0 V more negative than that of LDH, favorable for the electron injection to LDH and enabling a more efficient hole separation. The enhanced photon-to-current conversion efficiency and improved water oxidation efficiency of the triadic structure may result from the non-negligible contribution of hot electrons or holes generated in QDs. Such a band-matching and multidimensional triadic architecture could be a promising strategy for achieving high-efficiency photoanodes by sufficiently utilizing and maximizing the functionalities of QDs.« less

Integrating Scientific Array Processing into Standard SQL

NASA Astrophysics Data System (ADS)

Misev, Dimitar; Bachhuber, Johannes; Baumann, Peter

2014-05-01

We live in a time that is dominated by data. Data storage is cheap and more applications than ever accrue vast amounts of data. Storing the emerging multidimensional data sets efficiently, however, and allowing them to be queried by their inherent structure, is a challenge many databases have to face today. Despite the fact that multidimensional array data is almost always linked to additional, non-array information, array databases have mostly developed separately from relational systems, resulting in a disparity between the two database categories. The current SQL standard and SQL DBMS supports arrays - and in an extension also multidimensional arrays - but does so in a very rudimentary and inefficient way. This poster demonstrates the practicality of an SQL extension for array processing, implemented in a proof-of-concept multi-faceted system that manages a federation of array and relational database systems, providing transparent, efficient and scalable access to the heterogeneous data in them.

Mergeomics: a web server for identifying pathological pathways, networks, and key regulators via multidimensional data integration.

PubMed

Arneson, Douglas; Bhattacharya, Anindya; Shu, Le; Mäkinen, Ville-Petteri; Yang, Xia

2016-09-09

Human diseases are commonly the result of multidimensional changes at molecular, cellular, and systemic levels. Recent advances in genomic technologies have enabled an outpour of omics datasets that capture these changes. However, separate analyses of these various data only provide fragmented understanding and do not capture the holistic view of disease mechanisms. To meet the urgent needs for tools that effectively integrate multiple types of omics data to derive biological insights, we have developed Mergeomics, a computational pipeline that integrates multidimensional disease association data with functional genomics and molecular networks to retrieve biological pathways, gene networks, and central regulators critical for disease development. To make the Mergeomics pipeline available to a wider research community, we have implemented an online, user-friendly web server ( http://mergeomics. idre.ucla.edu/ ). The web server features a modular implementation of the Mergeomics pipeline with detailed tutorials. Additionally, it provides curated genomic resources including tissue-specific expression quantitative trait loci, ENCODE functional annotations, biological pathways, and molecular networks, and offers interactive visualization of analytical results. Multiple computational tools including Marker Dependency Filtering (MDF), Marker Set Enrichment Analysis (MSEA), Meta-MSEA, and Weighted Key Driver Analysis (wKDA) can be used separately or in flexible combinations. User-defined summary-level genomic association datasets (e.g., genetic, transcriptomic, epigenomic) related to a particular disease or phenotype can be uploaded and computed real-time to yield biologically interpretable results, which can be viewed online and downloaded for later use. Our Mergeomics web server offers researchers flexible and user-friendly tools to facilitate integration of multidimensional data into holistic views of disease mechanisms in the form of tissue-specific key regulators, biological pathways, and gene networks.

Multidimensional Signal Processing for Sensing & Communications

DTIC Science & Technology

2015-07-29

Superresolution (RISR) Algorithm,” IEEE Radar Conference, Cincinnati, OH, 19-23 May 2014, pp. 1278-1282. 5. J. Jakabosky, S.D. Blunt, and B. Himed...2014. B.D. Cordill, S.A. Seguin, and S.D. Blunt, “Mutual Coupling Calibration using the Reiterative Superresolution (RISR) Algorithm,” IEEE Radar

Multidimensional joint coupling: a case study visualisation approach to movement coordination and variability.

PubMed

Irwin, Gareth; Kerwin, David G; Williams, Genevieve; Van Emmerik, Richard E A; Newell, Karl M; Hamill, Joseph

2018-06-18

A case study visualisation approach to examining the coordination and variability of multiple interacting segments is presented using a whole-body gymnastic skill as the task example. One elite male gymnast performed 10 trials of 10 longswings whilst three-dimensional locations of joint centres were tracked using a motion analysis system. Segment angles were used to define coupling between the arms and trunk, trunk and thighs and thighs and shanks. Rectified continuous relative phase profiles for each interacting couple for 80 longswings were produced. Graphical representations of coordination couplings are presented that include the traditional single coupling, followed by the relational dynamics of two couplings and finally three couplings simultaneously plotted. This method highlights the power of visualisation of movement dynamics and identifies properties of the global interacting segmental couplings that a more formal analysis may not reveal. Visualisation precedes and informs the appropriate qualitative and quantitative analysis of the dynamics.

A multidimensional representation model of geographic features

USGS Publications Warehouse

Usery, E. Lynn; Timson, George; Coletti, Mark

2016-01-28

A multidimensional model of geographic features has been developed and implemented with data from The National Map of the U.S. Geological Survey. The model, programmed in C++ and implemented as a feature library, was tested with data from the National Hydrography Dataset demonstrating the capability to handle changes in feature attributes, such as increases in chlorine concentration in a stream, and feature geometry, such as the changing shoreline of barrier islands over time. Data can be entered directly, from a comma separated file, or features with attributes and relationships can be automatically populated in the model from data in the Spatial Data Transfer Standard format.

Electrochemical force microscopy

DOEpatents

Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam F.; Rodriguez, Brian J.

2017-01-10

A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

The Use of the Visualisation of Multidimensional Data Using PCA to Evaluate Possibilities of the Division of Coal Samples Space Due to their Suitability for Fluidised Gasification

NASA Astrophysics Data System (ADS)

Jamróz, Dariusz; Niedoba, Tomasz; Surowiak, Agnieszka; Tumidajski, Tadeusz

2016-09-01

Methods serving to visualise multidimensional data through the transformation of multidimensional space into two-dimensional space, enable to present the multidimensional data on the computer screen. Thanks to this, qualitative analysis of this data can be performed in the most natural way for humans, through the sense of sight. An example of such a method of multidimensional data visualisation is PCA (principal component analysis) method. This method was used in this work to present and analyse a set of seven-dimensional data (selected seven properties) describing coal samples obtained from Janina and Wieczorek coal mines. Coal from these mines was previously subjected to separation by means of a laboratory ring jig, consisting of ten rings. With 5 layers of both types of coal (with 2 rings each) were obtained in this way. It was decided to check if the method of multidimensional data visualisation enables to divide the space of such divided samples into areas with different suitability for the fluidised gasification process. To that end, the card of technological suitability of coal was used (Sobolewski et al., 2012; 2013), in which key, relevant and additional parameters, having effect on the gasification process, were described. As a result of analyses, it was stated that effective determination of coal samples suitability for the on-surface gasification process in a fluidised reactor is possible. The PCA method enables the visualisation of the optimal subspace containing the set requirements concerning the properties of coals intended for this process.

A dynamic nuclear polarization strategy for multi-dimensional Earth's field NMR spectroscopy.

PubMed

Halse, Meghan E; Callaghan, Paul T

2008-12-01

Dynamic nuclear polarization (DNP) is introduced as a powerful tool for polarization enhancement in multi-dimensional Earth's field NMR spectroscopy. Maximum polarization enhancements, relative to thermal equilibrium in the Earth's magnetic field, are calculated theoretically and compared to the more traditional prepolarization approach for NMR sensitivity enhancement at ultra-low fields. Signal enhancement factors on the order of 3000 are demonstrated experimentally using DNP with a nitroxide free radical, TEMPO, which contains an unpaired electron which is strongly coupled to a neighboring (14)N nucleus via the hyperfine interaction. A high-quality 2D (19)F-(1)H COSY spectrum acquired in the Earth's magnetic field with DNP enhancement is presented and compared to simulation.

[The study of unions in demography: from categories to process].

PubMed

Burch, T K; Belanger, D

1999-01-01

For centuries, illegitimate children, those born outside of civil marriage or a marriage conducted within the church, were systematically accorded second-class status by both the law and religion. This attitude toward such children frustrates efforts to change legislation, social structure, and our understanding of new types of union outside of marriage. In Canada, no common term even exists in the two official languages to designate the cohabitation of an unmarried couple. Such unions simply fall through the net of classical demography. Even the more dynamic approaches, such as those seen in multistate models, follow only the movements of individuals in traditional categories. One must understand that the formation of couples is a multidimensional process and that a multidimensional approach to such unions could lead to the creation of a new group of nonethnocentric categories applicable to a number of different societies. The authors also consider the notion of process, in which marriage and cohabitation are merely two states in a range of possible states through which an individual will move during the course of his or her life. Cohabiting situations vary in importance depending upon one¿s states. Better demographic analyses can lead to greater understanding of the human couple and its sexual and reproductive behaviors.

The Nature of Science Instrument-Elementary (NOSI-E): Using Rasch principles to develop a theoretically grounded scale to measure elementary student understanding of the nature of science

NASA Astrophysics Data System (ADS)

Peoples, Shelagh

The purpose of this study was to determine which of three competing models will provide, reliable, interpretable, and responsive measures of elementary students' understanding of the nature of science (NOS). The Nature of Science Instrument-Elementary (NOSI-E), a 28-item Rasch-based instrument, was used to assess students' NOS understanding. The NOS construct was conceptualized using five construct dimensions (Empirical, Inventive, Theory-laden, Certainty and Socially & Culturally Embedded). The competing models represent three internal models for the NOS construct. One postulate is that the NOS construct is unidimensional where one latent construct explains the relationship between the 28 items of the NOSI-E. Alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. A validity argument was developed that hypothesized that the internal structure of the NOS construct is best represented by the multidimensional Rasch model. Four sets of analyses were performed in which the three representations were compared. These analyses addressed five validity aspects (content, substantive, generalizability, structural and external) of construct validity. The vast body of evidence supported the claim that the NOS construct is composed of five separate but inter-related dimensions that is best represented by the multidimensional Rasch model. The results of the multidimensional analyses indicated that the items of the five subscales were of excellent technical quality, exhibited no differential item functioning (based on gender), had an item hierarchy that conformed to theoretical expectations; and together formed subscales of reasonable reliability (> 0.7 on each subscale) that were responsive to change in the construct. Theory-laden scores from the multidimensional model predicted students' science achievement with scores from all five NOS dimensions significantly predicting students' perceptions of the constructivist nature of their classroom learning environment. The NOSI-E instrument is a theoretically grounded scale that can measure elementary students' NOS understanding and appears suitable for use in science education research.

NMR of lignins

Treesearch

John Ralph; Larry L. Landucci

2010-01-01

This chapter will consider the basic aspects and findings of several forms of NMR spectroscopy, including separate discussions of proton, carbon, heteronuclear, and multidimensional NMR. Enhanced focus will be on 13C NMR, because of its qualitative and quantitative importance, followed by NMR’s contributions to our understanding of lignin...

Multidimensionally constrained relativistic mean-field study of triple-humped barriers in actinides

NASA Astrophysics Data System (ADS)

Zhao, Jie; Lu, Bing-Nan; Vretenar, Dario; Zhao, En-Guang; Zhou, Shan-Gui

2015-01-01

Background: Potential energy surfaces (PES's) of actinide nuclei are characterized by a two-humped barrier structure. At large deformations beyond the second barrier, the occurrence of a third barrier was predicted by macroscopic-microscopic model calculations in the 1970s, but contradictory results were later reported by a number of studies that used different methods. Purpose: Triple-humped barriers in actinide nuclei are investigated in the framework of covariant density functional theory (CDFT). Methods: Calculations are performed using the multidimensionally constrained relativistic mean field (MDC-RMF) model, with the nonlinear point-coupling functional PC-PK1 and the density-dependent meson exchange functional DD-ME2 in the particle-hole channel. Pairing correlations are treated in the BCS approximation with a separable pairing force of finite range. Results: Two-dimensional PES's of 226,228,230,232Th and 232,235,236,238U are mapped and the third minima on these surfaces are located. Then one-dimensional potential energy curves along the fission path are analyzed in detail and the energies of the second barrier, the third minimum, and the third barrier are determined. The functional DD-ME2 predicts the occurrence of a third barrier in all Th nuclei and 238U . The third minima in 230 ,232Th are very shallow, whereas those in 226 ,228Th and 238U are quite prominent. With the functional PC-PK1 a third barrier is found only in 226 ,228 ,230Th . Single-nucleon levels around the Fermi surface are analyzed in 226Th, and it is found that the formation of the third minimum is mainly due to the Z =90 proton energy gap at β20≈1.5 and β30≈0.7 . Conclusions: The possible occurrence of a third barrier on the PES's of actinide nuclei depends on the effective interaction used in multidimensional CDFT calculations. More pronounced minima are predicted by the DD-ME2 functional, as compared to the functional PC-PK1. The depth of the third well in Th isotopes decreases with increasing neutron number. The origin of the third minimum is due to the proton Z =90 shell gap at relevant deformations.

Multidimensional Perfectionism and Internalizing Problems: Do Teacher and Classmate Support Matter?

ERIC Educational Resources Information Center

Fredrick, Stephanie Secord; Demaray, Michelle Kilpatrick; Jenkins, Lyndsay N.

2017-01-01

Adolescent stressors coupled with environmental demands, such as pressures to achieve, might lead to negative outcomes for some students. Students who worry about their ability to meet high standards might be more at risk of internalizing problems. The current study investigated the relations among perfectionism, social support, and internalizing…

The Division of Household Labor: Longitudinal Changes and Within-Couple Variation.

PubMed

Lam, Chun Bun; McHale, Susan M; Crouter, Ann C

2012-10-01

This study examined how the division of household labor changed as a function of marital duration and whether within-couple variation in spouses' relative power and availability were linked to within-couple variation in the division of labor. On 4 occasions over 7 years, 188 stably married couples reported on their housework activities using daily diaries. Multilevel models revealed that wives' portions of household responsibilities declined over time, and that changes in spouses' relative income and work hours were linked to changes in housework allocation. Wives with husbands who perceived greater marital control, on average, did proportionally more housework, and for couples with husbands who had highly autonomous jobs, changes in spouses' relative psychological job involvement were linked to changes in housework allocation. Findings highlight the importance of understanding household division of labor as a lifespan phenomenon, the distinction between within- versus between-couple associations, and the multidimensional nature of power and availability.

Conceptualizing the multidimensional nature of self-efficacy: assessment of situational context and level of behavioral challenge to maintain safer sex. National Institute of Mental Health Multisite HIV Prevention Trial Group.

PubMed

Murphy, D A; Stein, J A; Schlenger, W; Maibach, E

2001-07-01

A. Bandura (1991) argued that self-efficacy measurement should be specific both to the situation in which the behavior occurs and level of challenge in that situation. Measures consistent with the 2 dimensions were developed with graded challenge levels and differing gender-appropriate situations. Participants were 1,496 controls in the National Institute of Mental Health Multisite HIV Prevention Trial recruited from STD clinics and health service centers (925 women and 571 men). The authors tested 4 separate-sex confirmatory factor analysis models as follows: (a) Condom negotiation efficacy as a unitary construct across situations and gradation of difficulty; (b) situation as preeminent, which transfers across skills whatever the gradation of difficulty; (c) skill as predominant, irrespective of situation; and (d) a multidimensional design that simultaneously accounts for both situation and graded difficulty. Consistent with Bandura's theory, the multidimensional model provided the best fit for both samples.

Spectroscopic determination of the intermolecular potential energy surface for Ar-NH3

NASA Astrophysics Data System (ADS)

Schmuttenmaer, C. A.; Cohen, R. C.; Saykally, R. J.

1994-07-01

The three-dimensional intermolecular potential energy surface (IPS) for Ar-NH3 has been determined from a least-squares fit to 61 far infrared and microwave vibration-rotation-tunneling (VRT) measurements and to temperature-dependent second virial coefficients. The three intermolecular coordinates (R,θ,φ) are treated without invoking any approximations regarding their separability, and the NH3 inversion-tunneling motion is included adiabatically. A surface with 13 variable parameters has been optimized to accurately reproduce the spectroscopic observables, using the collocation method to treat the coupled multidimensional dynamics within a scattering formalism. Anisotropy in the IPS is found to significantly mix the free rotor basis functions. The 149.6 cm-1 global minimum on this surface occurs with the NH3 symmetry axis nearly perpendicular to the van der Waals bond axis (θ=96.6°), at a center-of-mass separation of 3.57 Å, and with the Ar atom midway between two of the NH3 hydrogen atoms (φ=60°). The position of the global minimum is very different from the center-of-mass distance extracted from microwave spectroscopic studies. Long-range (R≳3.8 Å) attractive interactions are greatest when either a N-H bond or the NH3 lone pair is directed toward the argon. Comparisons with ab initio surfaces for this molecule as well as the experimentally determined IPS for Ar-H2O are presented.

Structuring Program Analysis for Educational Research.

ERIC Educational Resources Information Center

Levine, Donald M.

Education is too complex, multidimensional, and poorly understood to lend itself to a single cost/effectiveness criterion. Rather, analysts in the educational field seek to rank alternatives by their effectiveness, report separately on the cost implications, and leave the tradeoffs to the decisionmaker's judgment. In this context, a program is any…

Two Aspects of the Therapeutic Alliance: Differential Relations with Depressive Symptom Change

ERIC Educational Resources Information Center

Webb, Christian A.; Derubeis, Robert J.; Amsterdam, Jay D.; Shelton, Richard C.; Hollon, Steven D.; Dimidjian, Sona

2011-01-01

Objective: The therapeutic alliance has been linked to symptom change in numerous investigations. Although the alliance is commonly conceptualized as a multidimensional construct, few studies have examined its components separately. The current study explored which components of the alliance are most highly associated with depressive symptom…

Preliminary Development of a Multidimensional Semantic Patient Experience Measurement Questionnaire.

PubMed

Kleiss, James A

2016-10-01

The purpose of this research was to assess the utility and reliability of a multidimensional patient experience measurement questionnaire in a clinical setting. Patient experience has emerged as an important metric for quality of healthcare. A number of separate concepts have been used to measure patient experience, but psychological research suggests that subjective experience is actually a composite of several independent concepts including: (a) evaluation/valence, (b) potency/control, (c) activity/arousal, and (d) novelty. The present research evaluates the reliability of a multidimensional patient experience measurement questionnaire in a clinical setting. A multidimensional semantic differential questionnaire was developed to measure the four underlying semantic dimensions of patient experience mentioned above. A group of 60 patients used the questionnaire to assess prescan expectations and postscan experience of a magnetic resonance scan. Data for one patient were deleted because their scan was interrupted. Results revealed more positive evaluation/valence, higher potency/control, and lower activity/arousal for postscan ratings compared to prescan expectations. Ratings of novelty were neutral in both the prescan and the postscan conditions. Subsequent analysis suggested that internal consistency for some concepts could be improved by replacing several specific rating scales. Present results provide evidence of the utility and reliability of a multidimensional semantic questionnaire for measuring patient experience in an actual clinical setting. Recommendations to improve internal consistency for the concepts potency/control, activity/arousal, and novelty were also provided. © The Author(s) 2016.

Multidimensional data analysis in immunophenotyping.

PubMed

Loken, M R

2001-05-01

The complexity of cell populations requires careful selection of reagents to detect cells of interest and distinguish them from other types. Additional reagents are frequently used to provide independent criteria for cell identification. Two or three monoclonal antibodies in combination with forward and right-angle light scatter generate a data set that is difficult to visualize because the data must be represented in four- or five-dimensional space. The separation between cell populations provided by the multiple characteristics is best visualized by multidimensional analysis using all parameters simultaneously to identify populations within the resulting hyperspace. Groups of cells are distinguished based on a combination of characteristics not apparent in any usual two-dimensional representation of the data.

Global Langevin model of multidimensional biomolecular dynamics.

PubMed

Schaudinnus, Norbert; Lickert, Benjamin; Biswas, Mithun; Stock, Gerhard

2016-11-14

Molecular dynamics simulations of biomolecular processes are often discussed in terms of diffusive motion on a low-dimensional free energy landscape F(). To provide a theoretical basis for this interpretation, one may invoke the system-bath ansatz á la Zwanzig. That is, by assuming a time scale separation between the slow motion along the system coordinate x and the fast fluctuations of the bath, a memory-free Langevin equation can be derived that describes the system's motion on the free energy landscape F(), which is damped by a friction field and driven by a stochastic force that is related to the friction via the fluctuation-dissipation theorem. While the theoretical formulation of Zwanzig typically assumes a highly idealized form of the bath Hamiltonian and the system-bath coupling, one would like to extend the approach to realistic data-based biomolecular systems. Here a practical method is proposed to construct an analytically defined global model of structural dynamics. Given a molecular dynamics simulation and adequate collective coordinates, the approach employs an "empirical valence bond"-type model which is suitable to represent multidimensional free energy landscapes as well as an approximate description of the friction field. Adopting alanine dipeptide and a three-dimensional model of heptaalanine as simple examples, the resulting Langevin model is shown to reproduce the results of the underlying all-atom simulations. Because the Langevin equation can also be shown to satisfy the underlying assumptions of the theory (such as a delta-correlated Gaussian-distributed noise), the global model provides a correct, albeit empirical, realization of Zwanzig's formulation. As an application, the model can be used to investigate the dependence of the system on parameter changes and to predict the effect of site-selective mutations on the dynamics.

Computational study of the reactions of methanol with the hydroperoxyl and methyl radicals. 2. Accurate thermal rate constants.

PubMed

Alecu, I M; Truhlar, Donald G

2011-12-29

Multistructural canonical variational-transition-state theory with multidimensional tunneling (MS-CVT/MT) is employed to calculate thermal rate constants for the abstraction of hydrogen atoms from both positions of methanol by the hydroperoxyl and methyl radicals over the temperature range 100-3000 K. The M08-HX hybrid meta-generalized gradient approximation density functional and M08-HX with specific reaction parameters, both with the maug-cc-pVTZ basis set, were validated in part 1 of this study (Alecu, I. M.; Truhlar, D. G. J. Phys. Chem. A2011, 115, 2811) against highly accurate CCSDT(2)(Q)/CBS calculations for the energetics of these reactions, and they are used here to compute the properties of all stationary points and the energies, gradients, and Hessians of nonstationary points along each considered reaction path. The internal rotations in some of the transition states are found to be highly anharmonic and strongly coupled to each other, and they generate multiple structures (conformations) whose contributions are included in the partition function. It is shown that the previous estimates for these rate constants used to build kinetic models for the combustion of methanol, some of which were based on transition state theory calculations with one-dimensional tunneling corrections and harmonic-oscillator approximations or separable one-dimensional hindered rotor treatments of torsions, are appreciably different than the ones presently calculated using MS-CVT/MT. The rate constants obtained from the best MS-CVT/MT calculations carried out in this study, in which the important effects of corner cutting due to small and large reaction path curvature are captured via a microcanonical optimized multidimensional tunneling (μOMT) treatment, are recommended for future refinement of the kinetic model for methanol combustion. © 2011 American Chemical Society

Global Langevin model of multidimensional biomolecular dynamics

NASA Astrophysics Data System (ADS)

Schaudinnus, Norbert; Lickert, Benjamin; Biswas, Mithun; Stock, Gerhard

2016-11-01

Molecular dynamics simulations of biomolecular processes are often discussed in terms of diffusive motion on a low-dimensional free energy landscape F ( 𝒙 ) . To provide a theoretical basis for this interpretation, one may invoke the system-bath ansatz á la Zwanzig. That is, by assuming a time scale separation between the slow motion along the system coordinate x and the fast fluctuations of the bath, a memory-free Langevin equation can be derived that describes the system's motion on the free energy landscape F ( 𝒙 ) , which is damped by a friction field and driven by a stochastic force that is related to the friction via the fluctuation-dissipation theorem. While the theoretical formulation of Zwanzig typically assumes a highly idealized form of the bath Hamiltonian and the system-bath coupling, one would like to extend the approach to realistic data-based biomolecular systems. Here a practical method is proposed to construct an analytically defined global model of structural dynamics. Given a molecular dynamics simulation and adequate collective coordinates, the approach employs an "empirical valence bond"-type model which is suitable to represent multidimensional free energy landscapes as well as an approximate description of the friction field. Adopting alanine dipeptide and a three-dimensional model of heptaalanine as simple examples, the resulting Langevin model is shown to reproduce the results of the underlying all-atom simulations. Because the Langevin equation can also be shown to satisfy the underlying assumptions of the theory (such as a delta-correlated Gaussian-distributed noise), the global model provides a correct, albeit empirical, realization of Zwanzig's formulation. As an application, the model can be used to investigate the dependence of the system on parameter changes and to predict the effect of site-selective mutations on the dynamics.

Proteome Analysis of Liver Cells Expressing a Full- Length Hepatitis C Virus (HCV) Replicon and Biopsy Specimens of Posttransplantation Liver from HCV-Infected Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs, Jon M.; Diamond, Deborah L.; Chan, Eric Y.

2005-06-01

The development of a reproducible model system for the study of Hepatitis C virus (HCV) infection has the potential to significantly enhance the study of virus-host interactions and provide future direction for modeling the pathogenesis of HCV. While there are studies describing global gene expression changes associated with HCV infection, changes in the proteome have not been characterized. We report the first large scale proteome analysis of the highly permissive Huh-7.5 cell line containing a full length HCV replicon. We detected > 4,400 proteins in this cell line, including HCV replicon proteins, using multidimensional liquid chromatographic (LC) separations coupled tomore » mass spectrometry (MS). The set of Huh-7.5 proteins confidently identified is, to our knowledge, the most comprehensive yet reported for a human cell line. Consistent with the literature, a comparison of Huh-7.5 cells (+) and (-) the HCV replicon identified expression changes of proteins involved in lipid metabolism. We extended these analyses to liver biopsy material from HCV-infected patients where > 1,500 proteins were detected from 2 {micro}g protein lysate using the Huh-7.5 protein database and the accurate mass and time (AMT) tag strategy. These findings demonstrate the utility of multidimensional proteome analysis of the HCV replicon model system for assisting the determination of proteins/pathways affected by HCV infection. Our ability to extend these analyses to the highly complex proteome of small liver biopsies with limiting protein yields offers the unique opportunity to begin evaluating the clinical significance of protein expression changes associated with HCV infection.« less

Multi-dimensional multi-species modeling of transient electrodeposition in LIGA microfabrication.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Gregory Herbert; Chen, Ken Shuang

2004-06-01

This report documents the efforts and accomplishments of the LIGA electrodeposition modeling project which was headed by the ASCI Materials and Physics Modeling Program. A multi-dimensional framework based on GOMA was developed for modeling time-dependent diffusion and migration of multiple charged species in a dilute electrolyte solution with reduction electro-chemical reactions on moving deposition surfaces. By combining the species mass conservation equations with the electroneutrality constraint, a Poisson equation that explicitly describes the electrolyte potential was derived. The set of coupled, nonlinear equations governing species transport, electric potential, velocity, hydrodynamic pressure, and mesh motion were solved in GOMA, using themore » finite-element method and a fully-coupled implicit solution scheme via Newton's method. By treating the finite-element mesh as a pseudo solid with an arbitrary Lagrangian-Eulerian formulation and by repeatedly performing re-meshing with CUBIT and re-mapping with MAPVAR, the moving deposition surfaces were tracked explicitly from start of deposition until the trenches were filled with metal, thus enabling the computation of local current densities that potentially influence the microstructure and frictional/mechanical properties of the deposit. The multi-dimensional, multi-species, transient computational framework was demonstrated in case studies of two-dimensional nickel electrodeposition in single and multiple trenches, without and with bath stirring or forced flow. Effects of buoyancy-induced convection on deposition were also investigated. To further illustrate its utility, the framework was employed to simulate deposition in microscreen-based LIGA molds. Lastly, future needs for modeling LIGA electrodeposition are discussed.« less

A Practical Illustration of Multidimensional Diagnostic Skills Profiling: Comparing Results from Confirmatory Factor Analysis and Diagnostic Classification Models

ERIC Educational Resources Information Center

Kunina-Habenicht, Olga; Rupp, Andre A.; Wilhelm, Oliver

2009-01-01

In recent years there has been an increasing international interest in fine-grained diagnostic inferences on multiple skills for formative purposes. A successful provision of such inferences that support meaningful instructional decision-making requires (a) careful diagnostic assessment design coupled with (b) empirical support for the structure…

A versatile embedded boundary adaptive mesh method for compressible flow in complex geometry

NASA Astrophysics Data System (ADS)

Al-Marouf, M.; Samtaney, R.

2017-05-01

We present an embedded ghost fluid method for numerical solutions of the compressible Navier Stokes (CNS) equations in arbitrary complex domains. A PDE multidimensional extrapolation approach is used to reconstruct the solution in the ghost fluid regions and imposing boundary conditions on the fluid-solid interface, coupled with a multi-dimensional algebraic interpolation for freshly cleared cells. The CNS equations are numerically solved by the second order multidimensional upwind method. Block-structured adaptive mesh refinement, implemented with the Chombo framework, is utilized to reduce the computational cost while keeping high resolution mesh around the embedded boundary and regions of high gradient solutions. The versatility of the method is demonstrated via several numerical examples, in both static and moving geometry, ranging from low Mach number nearly incompressible flows to supersonic flows. Our simulation results are extensively verified against other numerical results and validated against available experimental results where applicable. The significance and advantages of our implementation, which revolve around balancing between the solution accuracy and implementation difficulties, are briefly discussed as well.

A Deeper Understanding of Metacomprehension in Reading: Development of a New Multidimensional Tool

ERIC Educational Resources Information Center

Soto, Christian; Gutierrez de Blume, Antonio P.; Asún, Rodrigo; Jacovina, Matthew; Vásquez, Claudio

2018-01-01

The purpose of this research endeavor was to develop and validate a new measurement tool predicated on previous research to assess learners' metacomprehension during reading. In two separate studies with Chilean undergraduate students (N = 923), we demonstrate the versatility and utility of our proposed Metacomprehension Inventory (MI). In Study…

Theory of Mind and Empathy as Multidimensional Constructs: Neurological Foundations

ERIC Educational Resources Information Center

Dvash, Jonathan; Shamay-Tsoory, Simone G.

2014-01-01

Empathy describes an individual's ability to understand and feel the other. In this article, we review recent theoretical approaches to the study of empathy. Recent evidence supports 2 possible empathy systems: an emotional system and a cognitive system. These processes are served by separate, albeit interacting, brain networks. When a cognitive…

Positive Classroom Motivational Environments : Convergence between Mastery Goal Structure and Classroom Social Climate

ERIC Educational Resources Information Center

Patrick, Helen; Kaplan, Avi; Ryan, Allison M.

2011-01-01

In a series of 4 studies we investigated the relations of mastery goal structure and 4 dimensions of the classroom social climate (teacher academic support, teacher emotional support, classroom mutual respect, task-related interaction). We conducted multidimensional scaling with separate adolescent samples that differed considerably (i.e., by…

Disarming jealousy in couples relationships: a multidimensional approach.

PubMed

Scheinkman, Michele; Werneck, Denise

2010-12-01

Jealousy is a powerful emotional force in couples' relationships. In just seconds it can turn love into rage and tenderness into acts of control, intimidation, and even suicide or murder. Yet it has been surprisingly neglected in the couples therapy field. In this paper we define jealousy broadly as a hub of contradictory feelings, thoughts, beliefs, actions, and reactions, and consider how it can range from a normative predicament to extreme obsessive manifestations. We ground jealousy in couples' basic relational tasks and utilize the construct of the vulnerability cycle to describe processes of derailment. We offer guidelines on how to contain the couple's escalation, disarm their ineffective strategies and power struggles, identify underlying vulnerabilities and yearnings, and distinguish meanings that belong to the present from those that belong to the past, or to other contexts. The goal is to facilitate relational and personal changes that can yield a better fit between the partners' expectations. 2010 © FPI, Inc.

Multi-Dimensional Quantum Effect Simulation Using a Density-Gradient Model and Script-Level Programming Techniques

NASA Technical Reports Server (NTRS)

Rafferty, Connor S.; Biegel, Bryan A.; Yu, Zhi-Ping; Ancona, Mario G.; Bude, J.; Dutton, Robert W.; Saini, Subhash (Technical Monitor)

1998-01-01

A density-gradient (DG) model is used to calculate quantum-mechanical corrections to classical carrier transport in MOS (Metal Oxide Semiconductor) inversion/accumulation layers. The model is compared to measured data and to a fully self-consistent coupled Schrodinger and Poisson equation (SCSP) solver. Good agreement is demonstrated for MOS capacitors with gate oxide as thin as 21 A. It is then applied to study carrier distribution in ultra short MOSFETs (Metal Oxide Semiconductor Field Effect Transistor) with surface roughness. This work represents the first implementation of the DG formulation on multidimensional unstructured meshes. It was enabled by a powerful scripting approach which provides an easy-to-use and flexible framework for solving the fourth-order PDEs (Partial Differential Equation) of the DG model.

electromagnetics, eddy current, computer codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gartling, David

TORO Version 4 is designed for finite element analysis of steady, transient and time-harmonic, multi-dimensional, quasi-static problems in electromagnetics. The code allows simulation of electrostatic fields, steady current flows, magnetostatics and eddy current problems in plane or axisymmetric, two-dimensional geometries. TORO is easily coupled to heat conduction and solid mechanics codes to allow multi-physics simulations to be performed.

Using periodic line fires to gain a new perspective on multi-dimensional aspects of forward fire spread

Treesearch

R. R. Linn; J. M. Canfield; P. Cunningham; C. Edminster; J.-L. Dupuy; F. Pimont

2012-01-01

This study was conducted to increase understanding of possible roles and importance of local threedimensionality in the forward spread of wildfire models. A suite of simulations was performed using a coupled atmosphere-fire model, HIGRAD/FIRETEC, consisting of different scenarios that varied in domain width and boundary condition implementation. A subset of the...

The Role of Student Loan Programs in Higher Education Policy in the United States

ERIC Educational Resources Information Center

Amatya, Sachi

2009-01-01

The increasing cost of higher education, coupled with the inability of federal and state governments to sustain parallel increases in levels of funding for student financial aid, has led to significant growth of student loans. This project analyzes the multidimensional student loans space in the US. This project also compares and contrasts some of…

Mixed-bed ion exchange chromatography employing a salt-free pH gradient for improved sensitivity and compatibility in MudPIT.

PubMed

Mommen, Geert P M; Meiring, Hugo D; Heck, Albert J R; de Jong, Ad P J M

2013-07-16

In proteomics, comprehensive analysis of peptides mixtures necessitates multiple dimensions of separation prior to mass spectrometry analysis to reduce sample complexity and increase the dynamic range of analysis. The main goal of this work was to improve the performance of (online) multidimensional protein identification technology (MudPIT) in terms of sensitivity, compatibility and recovery. The method employs weak anion and strong cation mixed-bed ion exchange chromatography (ACE) in the first separation dimension and reversed phase chromatography (RP) in the second separation dimension (Motoyama et.al. Anal. Chem 2007, 79, 3623-34.). We demonstrated that the chromatographic behavior of peptides in ACE chromatography depends on both the WAX/SCX mixing ratio as the ionic strength of the mobile phase system. This property allowed us to replace the conventional salt gradient by a (discontinuous) salt-free, pH gradient. First dimensional separation of peptides was accomplished with mixtures of aqueous formic acid and dimethylsulfoxide with increasing concentrations. The overall performance of this mobile phase system was found comparable to ammonium acetate buffers in application to ACE chromatography, but clearly outperformed strong cation exchange for use in first dimensional peptide separation. The dramatically improved compatibility between (salt-free) ion exchange chromatography and reversed phase chromatography-mass spectrometry allowed us to downscale the dimensions of the RP analytical column down to 25 μm i.d. for an additional 2- to 3-fold improvement in performance compared to current technology. The achieved levels of sensitivity, orthogonality, and compatibility demonstrates the potential of salt-free ACE MudPIT for the ultrasensitive, multidimensional analysis of very modest amounts of sample material.

Homosexuality, Religion, and the Family: The Effects of Religion on Americans' Appraisals of the Parenting Abilities of Same-Sex Couples.

PubMed

Whitehead, Andrew L

2018-01-01

Although a growing body of research focuses on Americans' attitudes toward same-sex couples as parents, very few include measures of religion, and those that do fail to capture its multidimensional nature. Furthermore, many past studies relied on convenience samples of college students, or samples gathered outside the United States. Multivariate analyses of the 2012 General Social Survey-a nationally representative sample of adults in the United States-reveal that a slim majority of Americans still do not believe same-sex couples can parent as well as male-female couples, and the religious beliefs, behaviors, and affiliations of Americans are significantly and at times differentially associated with appraisals of same-sex couples' parenting abilities. It appears that although religion is generally associated with more negative appraisals of the parenting abilities of same-sex couples, it is not uniformly so. Americans' immediate religious and cultural context can shape their appraisals of homosexuality in diverse ways.

Separation and characterization of allergic polymerized impurities in cephalosporins by 2D-HPSEC×LC-IT-TOF MS.

PubMed

Xu, Yu; Wang, DanDan; Tang, Lan; Wang, Jian

2017-10-25

Eleven unknown allergic impurities in cefodizime, cefmenoxime and cefonicid were separated and characterized by a trap-free two-dimensional high performance size exclusion chromatography (HPSEC) and reversed phase liquid chromatography (RP-HPLC) coupled to high resolution ion trap/time-of-flight mass spectrometry (2D-HPSEC×LC-IT-TOF MS) with positive and negative modes of electrospray ionization method. Separation and characterization the allergic polymerized impurities in β-lactam antibiotics were on the basis of column-switching technique which effectively combined the advantages of HPSEC and the ability of RP-HPLC to identify the special impurities. In the first dimension HPSEC, the column was Xtimate SEC-120 analytical column (7.8mm×30cm, 5μm), and the gradient elution used pH 7.0 buffer-acetonitrile as mobile phase And the second dimension analytical column was ZORBAX SB-C18 (4.6×150mm, 3.5μm) with ammonium formate solution (10mM) and ammonium formate (8mM) in [acetonitrile-water (4:1, v/v)] solution as mobile phase. Structures of eleven unknown impurities were deduced based on the high resolution MS n data with both positive and negative modes, in which nine impurities were polymerized impurities. The forming mechanism of β-lactam antibiotic polymerization in cephalosporins was also studied. The question on incompatibility between non-volatile salt mobile phase and mass spectrometry was solved completely by multidimensional heart-cutting approaches and online demineralization technique, which was worthy of widespread use and application for the advantages of stability and repeatability. Copyright © 2017. Published by Elsevier B.V.

Feature combinations and the divergence criterion

NASA Technical Reports Server (NTRS)

Decell, H. P., Jr.; Mayekar, S. M.

1976-01-01

Classifying large quantities of multidimensional remotely sensed agricultural data requires efficient and effective classification techniques and the construction of certain transformations of a dimension reducing, information preserving nature. The construction of transformations that minimally degrade information (i.e., class separability) is described. Linear dimension reducing transformations for multivariate normal populations are presented. Information content is measured by divergence.

Exploring the Link between Mind Wandering, Mindfulness, and Creativity: A Multidimensional Approach

ERIC Educational Resources Information Center

Agnoli, Sergio; Vanucci, Manila; Pelagatti, Claudia; Corazza, Giovanni Emanuele

2018-01-01

Even if mind wandering (MW) and mindfulness have traditionally been intended as separate and antithetical constructs, the roles of these 2 mental states on creative behavior were jointly explored in this article. In particular, MW was analyzed in light of a recent approach suggesting a differentiation between deliberate and spontaneous MW, whereas…

Transcending the Quantitative-Qualitative Divide with Mixed Methods Research: A Multidimensional Framework for Understanding Congruence and Completeness in the Study of Values

ERIC Educational Resources Information Center

McLafferty, Charles L., Jr.; Slate, John R.; Onwuegbuzie, Anthony J.

2010-01-01

Quantitative research dominates published literature in the helping professions. Mixed methods research, which integrates quantitative and qualitative methodologies, has received a lukewarm reception. The authors address the iterative separation that infuses theory, praxis, philosophy, methodology, training, and public perception and propose a…

Teacher Effectiveness Examined as a System: Interpretive Structural Modeling and Facilitation Sessions with U.S. and Japanese Students

ERIC Educational Resources Information Center

Georgakopoulos, Alexia

2009-01-01

This study challenges narrow definitions of teacher effectiveness and uses a systems approach to investigate teacher effectiveness as a multi-dimensional, holistic phenomenon. The methods of Nominal Group Technique and Interpretive Structural Modeling were used to assist U.S. and Japanese students separately construct influence structures during…

Probing Lexical Representations: Simultaneous Modeling of Word and Reader Contributions to Multidimensional Lexical Representations

ERIC Educational Resources Information Center

Goodwin, Amanda P.; Gilbert, Jennifer K.; Cho, Sun-Joo; Kearns, Devin M.

2014-01-01

The current study models reader, item, and word contributions to the lexical representations of 39 morphologically complex words for 172 middle school students using a crossed random-effects item response model with multiple outcomes. We report 3 findings. First, results suggest that lexical representations can be characterized by separate but…

Multidimensional daily diary of fatigue-fibromyalgia-17 items (MDF-fibro-17). part 1: development and content validity.

PubMed

Morris, S; Li, Y; Smith, J A M; Dube', S; Burbridge, C; Symonds, T

2017-05-16

Fibromyalgia (FM), a disorder characterized by chronic widespread pain and tenderness, affects greater than five million individuals in the United States alone. Patients experience multiple symptoms in addition to pain, and among them, fatigue is one of the most bothersome and disabling. There is a growing body of literature suggesting that fatigue is a multidimensional concept. Currently, to our knowledge, no multidimensional Patient Reported Outcome (PRO) measure of FM-related fatigue meets Food and Drug Administration (FDA) requirements to support a product label claim. Therefore, the objective of this research was to evaluate qualitative and quantitative data previously gathered to inform the development of a comprehensive, multidimensional, PRO measure to assess FM-related fatigue in FM clinical trials. Existing qualitative and quantitative data from three previously conducted studies in patients with FM were reviewed to inform the initial development of a multidimensional PRO measure of FM-related fatigue: 1) a concept elicitation study involving in-depth, open-ended interviews with patients with FM in the United States (US) (N = 20), Germany (N = 10), and France (N = 10); 2) a cognitive debriefing and pilot study of a preliminary pool of 23 items (N = 20 US patients with FM); and 3) a methodology study that explored initial psychometrics of the item pool (N = 145 US patients with FM). Five domains were identified that intend to capture the broad experience of FM-related fatigue reported in the qualitative research: the Global Fatigue Experience, Cognitive Fatigue, Physical Fatigue, Motivation, and Impact on Function. Seventeen of the original pool of 23 items were selected to best capture these five dimensions. These 17 items formed the basis of a newly developed multidimensional PRO measure to assess FM-related fatigue in clinical trials: the Multidimensional Daily Diary of Fatigue-Fibromyalgia-17 (MDF-Fibro-17). Qualitative analysis, and preliminary quantitative item level data, confirmed that FM-related fatigue is multidimensional and provided strong support for the content validity of the MDF-Fibro-17. The next stage was to quantitatively evaluate the measure to confirm the factor structure, psychometric properties, sensitivity to change, and meaningful change. This has been conducted and is being reported separately.

Delay differential analysis of time series.

PubMed

Lainscsek, Claudia; Sejnowski, Terrence J

2015-03-01

Nonlinear dynamical system analysis based on embedding theory has been used for modeling and prediction, but it also has applications to signal detection and classification of time series. An embedding creates a multidimensional geometrical object from a single time series. Traditionally either delay or derivative embeddings have been used. The delay embedding is composed of delayed versions of the signal, and the derivative embedding is composed of successive derivatives of the signal. The delay embedding has been extended to nonuniform embeddings to take multiple timescales into account. Both embeddings provide information on the underlying dynamical system without having direct access to all the system variables. Delay differential analysis is based on functional embeddings, a combination of the derivative embedding with nonuniform delay embeddings. Small delay differential equation (DDE) models that best represent relevant dynamic features of time series data are selected from a pool of candidate models for detection or classification. We show that the properties of DDEs support spectral analysis in the time domain where nonlinear correlation functions are used to detect frequencies, frequency and phase couplings, and bispectra. These can be efficiently computed with short time windows and are robust to noise. For frequency analysis, this framework is a multivariate extension of discrete Fourier transform (DFT), and for higher-order spectra, it is a linear and multivariate alternative to multidimensional fast Fourier transform of multidimensional correlations. This method can be applied to short or sparse time series and can be extended to cross-trial and cross-channel spectra if multiple short data segments of the same experiment are available. Together, this time-domain toolbox provides higher temporal resolution, increased frequency and phase coupling information, and it allows an easy and straightforward implementation of higher-order spectra across time compared with frequency-based methods such as the DFT and cross-spectral analysis.

A novel hybrid approach with multidimensional-like effects for compressible flow computations

NASA Astrophysics Data System (ADS)

Kalita, Paragmoni; Dass, Anoop K.

2017-07-01

A multidimensional scheme achieves good resolution of strong and weak shocks irrespective of whether the discontinuities are aligned with or inclined to the grid. However, these schemes are computationally expensive. This paper achieves similar effects by hybridizing two schemes, namely, AUSM and DRLLF and coupling them through a novel shock switch that operates - unlike existing switches - on the gradient of the Mach number across the cell-interface. The schemes that are hybridized have contrasting properties. The AUSM scheme captures grid-aligned (and strong) shocks crisply but it is not so good for non-grid-aligned weaker shocks, whereas the DRLLF scheme achieves sharp resolution of non-grid-aligned weaker shocks, but is not as good for grid-aligned strong shocks. It is our experience that if conventional shock switches based on variables like density, pressure or Mach number are used to combine the schemes, the desired effect of crisp resolution of grid-aligned and non-grid-aligned discontinuities are not obtained. To circumvent this problem we design a shock switch based - for the first time - on the gradient of the cell-interface Mach number with very impressive results. Thus the strategy of hybridizing two carefully selected schemes together with the innovative design of the shock switch that couples them, affords a method that produces the effects of a multidimensional scheme with a lower computational cost. It is further seen that hybridization of the AUSM scheme with the recently developed DRLLFV scheme using the present shock switch gives another scheme that provides crisp resolution for both shocks and boundary layers. Merits of the scheme are established through a carefully selected set of numerical experiments.

Linear separability in superordinate natural language concepts.

PubMed

Ruts, Wim; Storms, Gert; Hampton, James

2004-01-01

Two experiments are reported in which linear separability was investigated in superordinate natural language concept pairs (e.g., toiletry-sewing gear). Representations of the exemplars of semantically related concept pairs were derived in two to five dimensions using multidimensional scaling (MDS) of similarities based on possession of the concept features. Next, category membership, obtained from an exemplar generation study (in Experiment 1) and from a forced-choice classification task (in Experiment 2) was predicted from the coordinates of the MDS representation using log linear analysis. The results showed that all natural kind concept pairs were perfectly linearly separable, whereas artifact concept pairs showed several violations. Clear linear separability of natural language concept pairs is in line with independent cue models. The violations in the artifact pairs, however, yield clear evidence against the independent cue models.

Characterization of the human submandibular/sublingual saliva glycoproteome using lectin affinity chromatography coupled to Multidimensional Protein Identification Technology

PubMed Central

Gonzalez-Begne, Mireya; Lu, Bingwen; Liao, Lujian; Xu, Tao; Bedi, Gurrinder; Melvin, James E.; Yates, John R.

2011-01-01

In-depth analysis of the salivary proteome is fundamental to understanding the functions of salivary proteins in the oral cavity and to reveal disease biomarkers involved in different pathophysiological conditions, with the ultimate goal of improving patient diagnosis and prognosis. Submandibular and sublingual glands contribute saliva rich in glycoproteins to the total saliva output, making them valuable sources for glycoproteomic analysis. Lectin-affinity chromatography coupled to mass spectrometry-based shotgun proteomics was used to explore the submandibular/sublingual (SM/SL) saliva glycoproteome. A total of 262 N- and O-linked glycoproteins were identified by multidimensional protein identification technology (MudPIT). Only 38 were previously described in SM and SL salivas from the human salivary N-linked glycoproteome, while 224 were unique. Further comparison analysis with SM/SL saliva of the human saliva proteome, revealed 125 glycoproteins not formerly reported in this secretion. KEGG pathway analyses demonstrated that many of these glycoproteins are involved in processes such as complement and coagulation cascades, cell communication, glycosphingolipid biosynthesis neo-lactoseries, O-glycan biosynthesis, glycan structures-biosynthesis 2, starch and sucrose metabolism, peptidoglycan biosynthesis or others pathways. In summary, lectin-affinity chromatography coupled to MudPIT mass spectrometry identified many novel glycoproteins in SM/SL saliva. These new additions to the salivary proteome may prove to be a critical step for providing reliable biomarkers in the diagnosis of a myriad of oral and systemic diseases. PMID:21936497

Multi-dimensional grating interferometer based on fibre-fed measurement heads arranged in Littrow configuration

NASA Astrophysics Data System (ADS)

Šiaudinytė, Lauryna; Molnar, Gabor; Köning, Rainer; Flügge, Jens

2018-05-01

Industrial application versatility of interferometric encoders increases the urge to measure several degrees of freedom. A novel grating interferometer containing a commercially available, minimized Michelson interferometer and three fibre-fed measurement heads is presented in this paper. Moreover, the arrangement is designed for simultaneous displacement measurements in two perpendicular planes. In the proposed setup, beam splitters are located in the fibre heads, therefore the grating is separated from the light source and the photo detector, which influence measurement results by generated heat. The operating principle of the proposed system as well as error sources influencing measurement results are discussed in this paper. Further, the benefits and shortcomings of the setup are presented. A simple Littrow-configuration-based design leads to a compact-size interferometric encoder suitable for multidimensional measurements.

Psychometric analysis of the Multidimensional Fatigue Inventory in a sample of persons treated for myocardial infarction.

PubMed

Fredriksson-Larsson, Ulla; Brink, Eva; Alsén, Pia; Falk, Kristin; Lundgren-Nilsson, Åsa

2015-01-01

Fatigue after myocardial infarction is a frequent and distressing symptom in the early recovery phase. The purpose of this study is to psychometrically evaluate the Multidimensional Fatigue Inventory (MFI-20). The MFI-20 was evaluated using Rasch analysis. The result showed that the MFI-20 can be used to obtain a global score reflecting an underlying unidimensional trait of fatigue; a transformation of the summarized raw scale scores into interval scale scores could be made. Also, 4 of the 5 original dimensions separately fitted the Rasch model. Calculation of a global score increases the possibility of identifying persons experiencing fatigue after myocardial infarction, and using the MFI-20 dimension scores increases the possibility of determining each person's specific fatigue profile.

Subjective evaluation with FAA criteria: A multidimensional scaling approach. [ground track control management

NASA Technical Reports Server (NTRS)

Kreifeldt, J. G.; Parkin, L.; Wempe, T. E.; Huff, E. F.

1975-01-01

Perceived orderliness in the ground tracks of five A/C during their simulated flights was studied. Dynamically developing ground tracks for five A/C from 21 separate runs were reproduced from computer storage and displayed on CRTS to professional pilots and controllers for their evaluations and preferences under several criteria. The ground tracks were developed in 20 seconds as opposed to the 5 minutes of simulated flight using speedup techniques for display. Metric and nonmetric multidimensional scaling techniques are being used to analyze the subjective responses in an effort to: (1) determine the meaningfulness of basing decisions on such complex subjective criteria; (2) compare pilot/controller perceptual spaces; (3) determine the dimensionality of the subjects' perceptual spaces; and thereby (4) determine objective measures suitable for comparing alternative traffic management simulations.

Immunoaffinity capillary electrophoresis as a powerful strategy for the quantification of low-abundance biomarkers, drugs, and metabolites in biological matrices

PubMed Central

Guzman, Norberto A.; Blanc, Timothy; Phillips, Terry M.

2009-01-01

In the last few years, there has been a greater appreciation by the scientific community of how separation science has contributed to the advancement of biomedical research. Despite past contributions in facilitating several biomedical breakthroughs, separation sciences still urgently need the development of improved methods for the separation and detection of biological and chemical substances. In particular, the challenging task of quantifying small molecules and biomolecules, found in low abundance in complex matrices (e.g., serum), is a particular area in need of new high-efficiency techniques. The tandem or on-line coupling of highly selective antibody capture agents with the high-resolving power of CE is being recognized as a powerful analytical tool for the enrichment and quantification of ultra-low abundance analytes in complex matrices. This development will have a significant impact on the identification and characterization of many putative biomarkers and on biomedical research in general. Immunoaffinity CE (IACE) technology is rapidly emerging as the most promising method for the analysis of low-abundance biomarkers; its power comes from a three-step procedure: (i) bioselective adsorption and (ii) subsequent recovery of compounds from an immobilized affinity ligand followed by (iii) separation of the enriched compounds. This technology is highly suited to automation and can be engineered to as a multiplex instrument capable of routinely performing hundreds of assays per day. Furthermore, a significant enhancement in sensitivity can be achieved for the purified and enriched affinity targeted analytes. Thus, a compound that exists in a complex biological matrix at a concentration far below its LOD is easily brought to well within its range of quantification. The present review summarizes several applications of IACE, as well as a chronological description of the improvements made in the fabrication of the analyte concentrator-microreactor device leading to the development of a multidimensional biomarker analyzer. PMID:18646282

Assessing the Multidimensional Relationship Between Medication Beliefs and Adherence in Older Adults With Hypertension Using Polynomial Regression.

PubMed

Dillon, Paul; Phillips, L Alison; Gallagher, Paul; Smith, Susan M; Stewart, Derek; Cousins, Gráinne

2018-02-05

The Necessity-Concerns Framework (NCF) is a multidimensional theory describing the relationship between patients' positive and negative evaluations of their medication which interplay to influence adherence. Most studies evaluating the NCF have failed to account for the multidimensional nature of the theory, placing the separate dimensions of medication "necessity beliefs" and "concerns" onto a single dimension (e.g., the Beliefs about Medicines Questionnaire-difference score model). To assess the multidimensional effect of patient medication beliefs (concerns and necessity beliefs) on medication adherence using polynomial regression with response surface analysis. Community-dwelling older adults >65 years (n = 1,211) presenting their own prescription for antihypertensive medication to 106 community pharmacies in the Republic of Ireland rated their concerns and necessity beliefs to antihypertensive medications at baseline and their adherence to antihypertensive medication at 12 months via structured telephone interview. Confirmatory polynomial regression found the difference-score model to be inaccurate; subsequent exploratory analysis identified a quadratic model to be the best-fitting polynomial model. Adherence was lowest among those with strong medication concerns and weak necessity beliefs, and adherence was greatest for those with weak concerns and strong necessity beliefs (slope β = -0.77, p<.001; curvature β = -0.26, p = .004). However, novel nonreciprocal effects were also observed; patients with simultaneously high concerns and necessity beliefs had lower adherence than those with simultaneously low concerns and necessity beliefs (slope β = -0.36, p = .004; curvature β = -0.25, p = .003). The difference-score model fails to account for the potential nonreciprocal effects. Results extend evidence supporting the use of polynomial regression to assess the multidimensional effect of medication beliefs on adherence.

Translation and Validation of the Multidimensional Dyspnea-12 Questionnaire.

PubMed

Amado Diago, Carlos Antonio; Puente Maestu, Luis; Abascal Bolado, Beatriz; Agüero Calvo, Juan; Hernando Hernando, Mercedes; Puente Bats, Irene; Agüero Balbín, Ramón

2018-02-01

Dyspnea is a multidimensional symptom, but this multidimensionality is not considered in most dyspnea questionnaires. The Dyspnea-12 takes a multidimensional approach to the assessment of dyspnea, specifically the sensory and the affective response. The objective of this study was to translate into Spanish and validate the Dyspnea-12 questionnaire. The original English version of the Dyspnea-12 questionnaire was translated into Spanish and backtranslated to analyze its equivalence. Comprehension of the text was verified by analyzing the responses of 10 patients. Reliability and validation of the questionnaire were studied in an independent group of COPD patients attending the pulmonology clinics of Hospital Universitario Marqués de Valdecilla, diagnosed and categorized according to GOLD guidelines. The mean age of the group (n=51) was 65 years and mean FEV1 was 50%. All patients understood all questions of the translated version of Dyspnea-12. Internal consistency of the questionnaire was α=0.937 and intraclass correlation coefficient was=.969; P<.001. Statistically significant correlations were found with HADS (anxiety r=.608 and depression r=.615), mMRC dyspnea (r=.592), 6MWT (r=-0.445), FEV1 (r=-0.312), all dimensions of CRQ-SAS (dyspnea r=-0.626; fatigue r=-0.718; emotional function r=-0.663; mastery r=-0.740), CAT (r=0.669), and baseline dyspnea index (r=-0.615). Dyspnea-12 scores were 10.32 points higher in symptomatic GOLD groups (B and D) (P<.001). The Spanish version of Dyspnea-12 is a valid and reliable instrument to study the multidimensional nature of dyspnea. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Structural sensitivity of Csbnd H vibrational band in methyl benzoate

NASA Astrophysics Data System (ADS)

Roy, Susmita; Maiti, Kiran Sankar

2018-05-01

The Csbnd H vibrational bands of methyl benzoate are studied to understand its coupling pattern with other vibrational bands of the biological molecule. This will facilitate to understand the biological structure and dynamics in spectroscopic as well as in microscopic study. Due to the congested spectroscopic pattern, near degeneracy, and strong anharmonicity of the Csbnd H stretch vibrations, assignment of the Csbnd H vibrational frequencies are often misleading. Anharmonic vibrational frequency calculation with multidimensional potential energy surface interprets the Csbnd H vibrational spectra more accurately. In this article we have presented the importance of multidimensional potential energy surface in anharmonic vibrational frequency calculation and discuss the unexpected red shift of asymmetric Csbnd H stretch vibration of methyl group. The Csbnd D stretch vibrational band which is splitted to double peaks due to the Fermi resonance is also discussed here.

Multidimensional Multiphysics Simulation of TRISO Particle Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. D. Hales; R. L. Williamson; S. R. Novascone

2013-11-01

Multidimensional multiphysics analysis of TRISO-coated particle fuel using the BISON finite-element based nuclear fuels code is described. The governing equations and material models applicable to particle fuel and implemented in BISON are outlined. Code verification based on a recent IAEA benchmarking exercise is described, and excellant comparisons are reported. Multiple TRISO-coated particles of increasing geometric complexity are considered. It is shown that the code's ability to perform large-scale parallel computations permits application to complex 3D phenomena while very efficient solutions for either 1D spherically symmetric or 2D axisymmetric geometries are straightforward. Additionally, the flexibility to easily include new physical andmore » material models and uncomplicated ability to couple to lower length scale simulations makes BISON a powerful tool for simulation of coated-particle fuel. Future code development activities and potential applications are identified.« less

Multidimensional Time-Resolved Spectroscopy of Vibrational Coherence in Biopolyenes

NASA Astrophysics Data System (ADS)

Buckup, Tiago; Motzkus, Marcus

2014-04-01

Multidimensional femtosecond time-resolved vibrational coherence spectroscopy allows one to investigate the evolution of vibrational coherence in electronic excited states. Methods such as pump-degenerate four-wave mixing and pump-impulsive vibrational spectroscopy combine an initial ultrashort laser pulse with a nonlinear probing sequence to reinduce vibrational coherence exclusively in the excited states. By carefully exploiting specific electronic resonances, one can detect vibrational coherence from 0 cm-1 to over 2,000 cm-1 and map its evolution. This review focuses on the observation and mapping of high-frequency vibrational coherence for all-trans biological polyenes such as β-carotene, lycopene, retinal, and retinal Schiff base. We discuss the role of molecular symmetry in vibrational coherence activity in the S1 electronic state and the interplay of coupling between electronic states and vibrational coherence.

Coupling effects for separate spatial solitons in a biased series centrosymmetric photorefractive crystal circuit considering grey solitons

NASA Astrophysics Data System (ADS)

Katti, Aavishkar; Yadav, Ram Anjore

2018-02-01

The existence and coupling of grey-grey, grey-bright and grey-dark separate spatial solitons in a biased series centrosymmetric photorefractive crystal circuit is investigated for the first time. The numerical solution of the separate spatial solitons is presented. The coupling between the two separate spatial solitons is analysed for all three cases of separate coupled solitons, namely grey-grey, grey-bright, and grey-dark. Changing the intensity of the soliton in one crystal affects the soliton in both crystals due to flow of the light induced current through the circuit. The effect of the background intensity of each crystal on both the spatial solitons is investigated. Also, the effect of changing the temperature of one crystal affects the soliton in both crystals due to the coupling effect. The soliton width dependence on the temperature is different for each crystal.

Dimensions of assertiveness: factor analysis of five assertion inventories.

PubMed

Henderson, M; Furnham, A

1983-09-01

Five self report assertiveness inventories were factor analyzed. In each case two major factors emerged, accounting for approximately one-quarter to a third of the variance. The findings emphasize the multidimensional nature of current measures of assertiveness, and suggest the construction of a more systematic and psychometrically evaluated scale that would yield subscale scores assessing the separate dimensions of assertiveness.

Theoretical description of quantum mechanical permeation of graphene membranes by charged hydrogen isotopes

NASA Astrophysics Data System (ADS)

Mazzuca, James W.; Haut, Nathaniel K.

2018-06-01

It has been recently shown that in the presence of an applied voltage, hydrogen and deuterium nuclei can be separated from one another using graphene membranes as a nuclear sieve, resulting in a 10-fold enhancement in the concentration of the lighter isotope. While previous studies, both experimental and theoretical, have attributed this effect mostly to differences in vibrational zero point energy (ZPE) of the various isotopes near the membrane surface, we propose that multi-dimensional quantum mechanical tunneling of nuclei through the graphene membrane influences this proton permeation process in a fundamental way. We perform ring polymer molecular dynamics calculations in which we include both ZPE and tunneling effects of various hydrogen isotopes as they permeate the graphene membrane and compute rate constants across a range of temperatures near 300 K. While capturing the experimentally observed separation factor, our calculations indicate that the transverse motion of the various isotopes across the surface of the graphene membrane is an essential part of this sieving mechanism. An understanding of the multi-dimensional quantum mechanical nature of this process could serve to guide the design of other such isotopic enrichment processes for a variety of atomic and molecular species of interest.

Multidimensional profiling of plasma lipoproteins by size exclusion chromatography followed by reverse-phase protein arrays

PubMed Central

Dernick, Gregor; Obermüller, Stefan; Mangold, Cyrill; Magg, Christine; Matile, Hugues; Gutmann, Oliver; von der Mark, Elisabeth; Handschin, Corinne; Maugeais, Cyrille; Niesor, Eric J.

2011-01-01

The composition of lipoproteins and the association of proteins with various particles are of much interest in the context of cardiovascular disease. Here, we describe a technique for the multidimensional analysis of lipoproteins and their associated apolipoproteins. Plasma is separated by size exclusion chromatography (SEC), and fractions are analyzed by reverse-phase arrays. SEC fractions are spotted on nitrocellulose slides and incubated with different antibodies against individual apolipoproteins or antibodies against various apolipoproteins. In this way, tens of analytes can be measured simultaneously in 100 μl of plasma from a single SEC separation. This methodology is particularly suited to simultaneous analysis of multiple proteins that may change their distribution to lipoproteins or alter their conformation, depending on factors that influence circulating lipoprotein size or composition. We observed changes in the distribution of exchangeable apolipoproteins following addition of recombinant apolipoproteins or interaction with exogenous compounds. While the cholesteryl ester transfer protein (CETP)-dependent formation of pre-β-HDL was inhibited by the CETP inhibitors torcetrapib and anacetrapib, it was not reduced by the CETP modulator dalcetrapib. This finding was elucidated using this technique. PMID:21971713

Theoretical description of quantum mechanical permeation of graphene membranes by charged hydrogen isotopes.

PubMed

Mazzuca, James W; Haut, Nathaniel K

2018-06-14

It has been recently shown that in the presence of an applied voltage, hydrogen and deuterium nuclei can be separated from one another using graphene membranes as a nuclear sieve, resulting in a 10-fold enhancement in the concentration of the lighter isotope. While previous studies, both experimental and theoretical, have attributed this effect mostly to differences in vibrational zero point energy (ZPE) of the various isotopes near the membrane surface, we propose that multi-dimensional quantum mechanical tunneling of nuclei through the graphene membrane influences this proton permeation process in a fundamental way. We perform ring polymer molecular dynamics calculations in which we include both ZPE and tunneling effects of various hydrogen isotopes as they permeate the graphene membrane and compute rate constants across a range of temperatures near 300 K. While capturing the experimentally observed separation factor, our calculations indicate that the transverse motion of the various isotopes across the surface of the graphene membrane is an essential part of this sieving mechanism. An understanding of the multi-dimensional quantum mechanical nature of this process could serve to guide the design of other such isotopic enrichment processes for a variety of atomic and molecular species of interest.

Application of Hyphenated Techniques in Speciation Analysis of Arsenic, Antimony, and Thallium

PubMed Central

Michalski, Rajmund; Szopa, Sebastian; Jabłońska, Magdalena; Łyko, Aleksandra

2012-01-01

Due to the fact that metals and metalloids have a strong impact on the environment, the methods of their determination and speciation have received special attention in recent years. Arsenic, antimony, and thallium are important examples of such toxic elements. Their speciation is especially important in the environmental and biomedical fields because of their toxicity, bioavailability, and reactivity. Recently, speciation analytics has been playing a unique role in the studies of biogeochemical cycles of chemical compounds, determination of toxicity and ecotoxicity of selected elements, quality control of food products, control of medicines and pharmaceutical products, technological process control, research on the impact of technological installation on the environment, examination of occupational exposure, and clinical analysis. Conventional methods are usually labor intensive, time consuming, and susceptible to interferences. The hyphenated techniques, in which separation method is coupled with multidimensional detectors, have become useful alternatives. The main advantages of those techniques consist in extremely low detection and quantification limits, insignificant interference, influence as well as high precision and repeatability of the determinations. In view of their importance, the present work overviews and discusses different hyphenated techniques used for arsenic, antimony, and thallium species analysis, in different clinical, environmental and food matrices. PMID:22654649

A compact and accurate semi-global potential energy surface for malonaldehyde from constrained least squares regression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizukami, Wataru, E-mail: wataru.mizukami@bristol.ac.uk; Tew, David P., E-mail: david.tew@bristol.ac.uk; Habershon, Scott, E-mail: S.Habershon@warwick.ac.uk

2014-10-14

We present a new approach to semi-global potential energy surface fitting that uses the least absolute shrinkage and selection operator (LASSO) constrained least squares procedure to exploit an extremely flexible form for the potential function, while at the same time controlling the risk of overfitting and avoiding the introduction of unphysical features such as divergences or high-frequency oscillations. Drawing from a massively redundant set of overlapping distributed multi-dimensional Gaussian functions of inter-atomic separations we build a compact full-dimensional surface for malonaldehyde, fit to explicitly correlated coupled cluster CCSD(T)(F12*) energies with a root mean square deviations accuracy of 0.3%–0.5% up tomore » 25 000 cm{sup −1} above equilibrium. Importance-sampled diffusion Monte Carlo calculations predict zero point energies for malonaldehyde and its deuterated isotopologue of 14 715.4(2) and 13 997.9(2) cm{sup −1} and hydrogen transfer tunnelling splittings of 21.0(4) and 3.2(4) cm{sup −1}, respectively, which are in excellent agreement with the experimental values of 21.583 and 2.915(4) cm{sup −1}.« less

Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

DOEpatents

Yeung, Edward S.; Chang, Yu-chen

1999-06-29

The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent.

Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

DOEpatents

Yeung, E.S.; Chang, Y.C.

1999-06-29

The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent. 8 figs.

Biofuel combustion. Energetics and kinetics of hydrogen abstraction from carbon-1 in n-butanol by the hydroperoxyl radical calculated by coupled cluster and density functional theories and multistructural variational transition-state theory with multidimensional tunneling.

PubMed

Alecu, I M; Zheng, Jingjing; Papajak, Ewa; Yu, Tao; Truhlar, Donald G

2012-12-20

Multistructural canonical variational transition-state theory with small-curvature multidimensional tunneling (MS-CVT/SCT) is employed to calculate thermal rate constants for hydrogen-atom abstraction from carbon-1 of n-butanol by the hydroperoxyl radical over the temperature range 250-2000 K. The M08-SO hybrid meta-GGA density functional was validated against CCSD(T)-F12a explicitly correlated wave function calculations with the jul-cc-pVTZ basis set. It was then used to compute the properties of all stationary points and the energies and Hessians of a few nonstationary points along the reaction path, which were then used to generate a potential energy surface by the multiconfiguration Shepard interpolation (MCSI) method. The internal rotations in the transition state for this reaction (like those in the reactant alcohol) are strongly coupled to each other and generate multiple stable conformations, which make important contributions to the partition functions. It is shown that neglecting to account for the multiple-structure effects and torsional potential anharmonicity effects that arise from the torsional modes would lead to order-of-magnitude errors in the calculated rate constants at temperatures of interest in combustion.

Multidimensional discrete compactons in nonlinear Schrödinger lattices with strong nonlinearity management

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Ambroise, J.; Salerno, M.; Kevrekidis, P. G.

The existence of multidimensional lattice compactons in the discrete nonlinear Schrödinger equation in the presence of fast periodic time modulations of the nonlinearity is demonstrated. By averaging over the period of the fast modulations, an effective averaged dynamical equation arises with coupling constants involving Bessel functions of the first and zeroth kinds. We show that these terms allow one to solve, at this averaged level, for exact discrete compacton solution configurations in the corresponding stationary equation. We focus on seven types of compacton solutions. Single-site and vortex solutions are found to be always stable in the parametric regimes we examined.more » We also found that other solutions such as double-site in- and out-of-phase, four-site symmetric and antisymmetric, and a five-site compacton solution are found to have regions of stability and instability in two-dimensional parametric planes, involving variations of the strength of the coupling and of the nonlinearity. We also explore the time evolution of the solutions and compare the dynamics according to the averaged equations with those of the original dynamical system. Finally, the possible observation of compactons in Bose-Einstein condensates loaded in a deep two-dimensional optical lattice with interactions modulated periodically in time is also discussed.« less

Multidimensional discrete compactons in nonlinear Schrödinger lattices with strong nonlinearity management

DOE PAGES

D'Ambroise, J.; Salerno, M.; Kevrekidis, P. G.; ...

2015-11-19

The existence of multidimensional lattice compactons in the discrete nonlinear Schrödinger equation in the presence of fast periodic time modulations of the nonlinearity is demonstrated. By averaging over the period of the fast modulations, an effective averaged dynamical equation arises with coupling constants involving Bessel functions of the first and zeroth kinds. We show that these terms allow one to solve, at this averaged level, for exact discrete compacton solution configurations in the corresponding stationary equation. We focus on seven types of compacton solutions. Single-site and vortex solutions are found to be always stable in the parametric regimes we examined.more » We also found that other solutions such as double-site in- and out-of-phase, four-site symmetric and antisymmetric, and a five-site compacton solution are found to have regions of stability and instability in two-dimensional parametric planes, involving variations of the strength of the coupling and of the nonlinearity. We also explore the time evolution of the solutions and compare the dynamics according to the averaged equations with those of the original dynamical system. Finally, the possible observation of compactons in Bose-Einstein condensates loaded in a deep two-dimensional optical lattice with interactions modulated periodically in time is also discussed.« less

Changes in frontal plane dynamics and the loading response phase of the gait cycle are characteristic of severe knee osteoarthritis application of a multidimensional analysis technique.

PubMed

Astephen, J L; Deluzio, K J

2005-02-01

Osteoarthritis of the knee is related to many correlated mechanical factors that can be measured with gait analysis. Gait analysis results in large data sets. The analysis of these data is difficult due to the correlated, multidimensional nature of the measures. A multidimensional model that uses two multivariate statistical techniques, principal component analysis and discriminant analysis, was used to discriminate between the gait patterns of the normal subject group and the osteoarthritis subject group. Nine time varying gait measures and eight discrete measures were included in the analysis. All interrelationships between and within the measures were retained in the analysis. The multidimensional analysis technique successfully separated the gait patterns of normal and knee osteoarthritis subjects with a misclassification error rate of <6%. The most discriminatory feature described a static and dynamic alignment factor. The second most discriminatory feature described a gait pattern change during the loading response phase of the gait cycle. The interrelationships between gait measures and between the time instants of the gait cycle can provide insight into the mechanical mechanisms of pathologies such as knee osteoarthritis. These results suggest that changes in frontal plane loading and alignment and the loading response phase of the gait cycle are characteristic of severe knee osteoarthritis gait patterns. Subsequent investigations earlier in the disease process may suggest the importance of these factors to the progression of knee osteoarthritis.

Manycore Performance-Portability: Kokkos Multidimensional Array Library

DOE PAGES

Edwards, H. Carter; Sunderland, Daniel; Porter, Vicki; ...

2012-01-01

Large, complex scientific and engineering application code have a significant investment in computational kernels to implement their mathematical models. Porting these computational kernels to the collection of modern manycore accelerator devices is a major challenge in that these devices have diverse programming models, application programming interfaces (APIs), and performance requirements. The Kokkos Array programming model provides library-based approach to implement computational kernels that are performance-portable to CPU-multicore and GPGPU accelerator devices. This programming model is based upon three fundamental concepts: (1) manycore compute devices each with its own memory space, (2) data parallel kernels and (3) multidimensional arrays. Kernel executionmore » performance is, especially for NVIDIA® devices, extremely dependent on data access patterns. Optimal data access pattern can be different for different manycore devices – potentially leading to different implementations of computational kernels specialized for different devices. The Kokkos Array programming model supports performance-portable kernels by (1) separating data access patterns from computational kernels through a multidimensional array API and (2) introduce device-specific data access mappings when a kernel is compiled. An implementation of Kokkos Array is available through Trilinos [Trilinos website, http://trilinos.sandia.gov/, August 2011].« less

Application of musical timbre discrimination features to active sonar classification

NASA Astrophysics Data System (ADS)

Young, Victor W.; Hines, Paul C.; Pecknold, Sean

2005-04-01

In musical acoustics significant effort has been devoted to uncovering the physical basis of timbre perception. Most investigations into timbre rely on multidimensional scaling (MDS), in which different musical sounds are arranged as points in multidimensional space. The Euclidean distance between points corresponds to the perceptual distance between sounds and the multidimensional axes are linked to measurable properties of the sounds. MDS has identified numerous temporal and spectral features believed to be important to timbre perception. There is reason to believe that some of these features may have wider application in the disparate field of underwater acoustics, since anecdotal evidence suggests active sonar returns from metallic objects sound different than natural clutter returns when auralized by human operators. This is particularly encouraging since attempts to develop robust automatic classifiers capable of target-clutter discrimination over a wide range of operational conditions have met with limited success. Spectral features relevant to target-clutter discrimination are believed to include click-pitch and envelope irregularity; relevant temporal features are believed to include duration, sub-band attack/decay time, and time separation pitch. Preliminary results from an investigation into the role of these timbre features in target-clutter discrimination will be presented. [Work supported by NSERC and GDC.

Coupling of TRAC-PF1/MOD2, Version 5.4.25, with NESTLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knepper, P.L.; Hochreiter, L.E.; Ivanov, K.N.

1999-09-01

A three-dimensional (3-D) spatial kinetics capability within a thermal-hydraulics system code provides a more correct description of the core physics during reactor transients that involve significant variations in the neutron flux distribution. Coupled codes provide the ability to forecast safety margins in a best-estimate manner. The behavior of a reactor core and the feedback to the plant dynamics can be accurately simulated. For each time step, coupled codes are capable of resolving system interaction effects on neutronics feedback and are capable of describing local neutronics effects caused by the thermal hydraulics and neutronics coupling. With the improvements in computational technology,more » modeling complex reactor behaviors with coupled thermal hydraulics and spatial kinetics is feasible. Previously, reactor analysis codes were limited to either a detailed thermal-hydraulics model with simplified kinetics or multidimensional neutron kinetics with a simplified thermal-hydraulics model. The authors discuss the coupling of the Transient Reactor Analysis Code (TRAC)-PF1/MOD2, Version 5.4.25, with the NESTLE code.« less

Online Nanoflow Multidimensional Fractionation for High Efficiency Phosphopeptide Analysis*

PubMed Central

Ficarro, Scott B.; Zhang, Yi; Carrasco-Alfonso, Marlene J.; Garg, Brijesh; Adelmant, Guillaume; Webber, James T.; Luckey, C. John; Marto, Jarrod A.

2011-01-01

Despite intense, continued interest in global analyses of signaling cascades through mass spectrometry-based studies, the large-scale, systematic production of phosphoproteomics data has been hampered in-part by inefficient fractionation strategies subsequent to phosphopeptide enrichment. Here we explore two novel multidimensional fractionation strategies for analysis of phosphopeptides. In the first technique we utilize aliphatic ion pairing agents to improve retention of phosphopeptides at high pH in the first dimension of a two-dimensional RP-RP. The second approach is based on the addition of strong anion exchange as the second dimension in a three-dimensional reversed phase (RP)-strong anion exchange (SAX)-RP configuration. Both techniques provide for automated, online data acquisition, with the 3-D platform providing the highest performance both in terms of separation peak capacity and the number of unique phosphopeptide sequences identified per μg of cell lysate consumed. Our integrated RP-SAX-RP platform provides several analytical figures of merit, including: (1) orthogonal separation mechanisms in each dimension; (2) high separation peak capacity (3) efficient retention of singly- and multiply-phosphorylated peptides; (4) compatibility with automated, online LC-MS analysis. We demonstrate the reproducibility of RP-SAX-RP and apply it to the analysis of phosphopeptides derived from multiple biological contexts, including an in vitro model of acute myeloid leukemia in addition to primary polyclonal CD8+ T-cells activated in vivo through bacterial infection and then purified from a single mouse. PMID:21788404

Gender Ideologies in Europe: A Multidimensional Framework.

PubMed

Grunow, Daniela; Begall, Katia; Buchler, Sandra

2018-02-01

The authors argue, in line with recent research, that operationalizing gender ideology as a unidimensional construct ranging from traditional to egalitarian is problematic and propose an alternative framework that takes the multidimensionality of gender ideologies into account. Using latent class analysis, they operationalize their gender ideology framework based on data from the 2008 European Values Study, of which eight European countries reflecting the spectrum of current work-family policies were selected. The authors examine the form in which gender ideologies cluster in the various countries. Five ideology profiles were identified: egalitarian, egalitarian essentialism, intensive parenting, moderate traditional, and traditional. The five ideology profiles were found in all countries, but with pronounced variation in size. Ideologies mixing gender essentialist and egalitarian views appear to have replaced traditional ideologies, even in countries offering some institutional support for gendered separate spheres.

Gender Ideologies in Europe: A Multidimensional Framework

PubMed Central

Begall, Katia; Buchler, Sandra

2018-01-01

The authors argue, in line with recent research, that operationalizing gender ideology as a unidimensional construct ranging from traditional to egalitarian is problematic and propose an alternative framework that takes the multidimensionality of gender ideologies into account. Using latent class analysis, they operationalize their gender ideology framework based on data from the 2008 European Values Study, of which eight European countries reflecting the spectrum of current work–family policies were selected. The authors examine the form in which gender ideologies cluster in the various countries. Five ideology profiles were identified: egalitarian, egalitarian essentialism, intensive parenting, moderate traditional, and traditional. The five ideology profiles were found in all countries, but with pronounced variation in size. Ideologies mixing gender essentialist and egalitarian views appear to have replaced traditional ideologies, even in countries offering some institutional support for gendered separate spheres. PMID:29491532

Multiphysics Simulations of Hot-Spot Initiation in Shocked Insensitive High-Explosive

NASA Astrophysics Data System (ADS)

Najjar, Fady; Howard, W. M.; Fried, L. E.

2010-11-01

Solid plastic-bonded high-explosive materials consist of crystals with micron-sized pores embedded. Under mechanical or thermal insults, these voids increase the ease of shock initiation by generating high-temperature regions during their collapse that might lead to ignition. Understanding the mechanisms of hot-spot initiation has significant research interest due to safety, reliability and development of new insensitive munitions. Multi-dimensional high-resolution meso-scale simulations are performed using the multiphysics software, ALE3D, to understand the hot-spot initiation. The Cheetah code is coupled to ALE3D, creating multi-dimensional sparse tables for the HE properties. The reaction rates were obtained from MD Quantum computations. Our current predictions showcase several interesting features regarding hot spot dynamics including the formation of a "secondary" jet. We will discuss the results obtained with hydro-thermo-chemical processes leading to ignition growth for various pore sizes and different shock pressures.

A practical nonlocal model for heat transport in magnetized laser plasmas

NASA Astrophysics Data System (ADS)

Nicolaï, Ph. D.; Feugeas, J.-L. A.; Schurtz, G. P.

2006-03-01

A model of nonlocal transport for multidimensional radiation magnetohydrodynamics codes is presented. In laser produced plasmas, it is now believed that the heat transport can be strongly modified by the nonlocal nature of the electron conduction. Other mechanisms, such as self-generated magnetic fields, may also affect the heat transport. The model described in this work, based on simplified Fokker-Planck equations aims at extending the model of G. Schurtz, Ph. Nicolaï, and M. Busquet [Phys. Plasmas 7, 4238 (2000)] to magnetized plasmas. A complete system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and simplified in order to be implemented into large laser fusion codes and coupled to other relevant physics. The model is applied to two laser configurations that demonstrate the main features of the model and point out the nonlocal Righi-Leduc effect in a multidimensional case.

Examining the Inseparability of Content Knowledge from LSP Reading Ability: An Approach Combining Bifactor-Multidimensional Item Response Theory and Structural Equation Modeling

ERIC Educational Resources Information Center

Cai, Yuyang; Kunnan, Antony John

2018-01-01

This study examined the separability of domain-general and domain-specific content knowledge from Language for Specific Purposes (LSP) reading ability. A pool of 1,491 nursing students in China participated by responding to a nursing English test and a nursing knowledge test. Primary data analysis involved four steps: (a) conducting a…

Monolignol radical-radical coupling networks in western red cedar and Arabidopsis and their evolutionary implications

NASA Technical Reports Server (NTRS)

Kim, Myoung K.; Jeon, Jae-Heung; Davin, Laurence B.; Lewis, Norman G.

2002-01-01

The discovery of a nine-member multigene dirigent family involved in control of monolignol radical-radical coupling in the ancient gymnosperm, western red cedar, suggested that a complex multidimensional network had evolved to regulate such processes in vascular plants. Accordingly, in this study, the corresponding promoter regions for each dirigent multigene member were obtained by genome-walking, with Arabidopsis being subsequently transformed to express each promoter fused to the beta-glucuronidase (GUS) reporter gene. It was found that each component gene of the proposed network is apparently differentially expressed in individual tissues, organs and cells at all stages of plant growth and development. The data so obtained thus further support the hypothesis that a sophisticated monolignol radical-radical coupling network exists in plants which has been highly conserved throughout vascular plant evolution.

Bargaining power within couples and use of prenatal and delivery care in Indonesia.

PubMed

Beegle, K; Frankenberg, E; Thomas, D

2001-06-01

Indonesian women's power relative to that of their husbands is examined to determine how it affects use of prenatal and delivery care. Holding household resources constant, a woman's control over economic resources affects the couple's decision-making. Compared with a woman with no assets that she perceives as being her own, a woman with some share of household assets influences reproductive health decisions. Evidence suggests that her influence on service use also varies if a woman is better educated than her husband, comes from a background of higher social status than her husband's, or if her father is better educated than her father-in-law. Therefore, both economic and social dimensions of the distribution of power between spouses influence use of services, and conceptualizing power as multidimensional is useful for understanding couples' behavior.

Does ℏ play a role in multidimensional spectroscopy? Reduced hierarchy equations of motion approach to molecular vibrations.

PubMed

Sakurai, Atsunori; Tanimura, Yoshitaka

2011-04-28

To investigate the role of quantum effects in vibrational spectroscopies, we have carried out numerically exact calculations of linear and nonlinear response functions for an anharmonic potential system nonlinearly coupled to a harmonic oscillator bath. Although one cannot carry out the quantum calculations of the response functions with full molecular dynamics (MD) simulations for a realistic system which consists of many molecules, it is possible to grasp the essence of the quantum effects on the vibrational spectra by employing a model Hamiltonian that describes an intra- or intermolecular vibrational motion in a condensed phase. The present model fully includes vibrational relaxation, while the stochastic model often used to simulate infrared spectra does not. We have employed the reduced quantum hierarchy equations of motion approach in the Wigner space representation to deal with nonperturbative, non-Markovian, and nonsecular system-bath interactions. Taking the classical limit of the hierarchy equations of motion, we have obtained the classical equations of motion that describe the classical dynamics under the same physical conditions as in the quantum case. By comparing the classical and quantum mechanically calculated linear and multidimensional spectra, we found that the profiles of spectra for a fast modulation case were similar, but different for a slow modulation case. In both the classical and quantum cases, we identified the resonant oscillation peak in the spectra, but the quantum peak shifted to the red compared with the classical one if the potential is anharmonic. The prominent quantum effect is the 1-2 transition peak, which appears only in the quantum mechanically calculated spectra as a result of anharmonicity in the potential or nonlinearity of the system-bath coupling. While the contribution of the 1-2 transition is negligible in the fast modulation case, it becomes important in the slow modulation case as long as the amplitude of the frequency fluctuation is small. Thus, we observed a distinct difference between the classical and quantum mechanically calculated multidimensional spectra in the slow modulation case where spectral diffusion plays a role. This fact indicates that one may not reproduce the experimentally obtained multidimensional spectrum for high-frequency vibrational modes based on classical molecular dynamics simulations if the modulation that arises from surrounding molecules is weak and slow. A practical way to overcome the difference between the classical and quantum simulations was discussed.

Enrichment and separation techniques for large-scale proteomics analysis of the protein post-translational modifications.

PubMed

Huang, Junfeng; Wang, Fangjun; Ye, Mingliang; Zou, Hanfa

2014-11-06

Comprehensive analysis of the post-translational modifications (PTMs) on proteins at proteome level is crucial to elucidate the regulatory mechanisms of various biological processes. In the past decades, thanks to the development of specific PTM enrichment techniques and efficient multidimensional liquid chromatography (LC) separation strategy, the identification of protein PTMs have made tremendous progress. A huge number of modification sites for some major protein PTMs have been identified by proteomics analysis. In this review, we first introduced the recent progresses of PTM enrichment methods for the analysis of several major PTMs including phosphorylation, glycosylation, ubiquitination, acetylation, methylation, and oxidation/reduction status. We then briefly summarized the challenges for PTM enrichment. Finally, we introduced the fractionation and separation techniques for efficient separation of PTM peptides in large-scale PTM analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of human plasma proteins: a focus on sample collection and separation using free-flow electrophoresis.

PubMed

Nissum, Mikkel; Foucher, Aude L

2008-08-01

Due to ease of accessibility, plasma has become the sample of choice for proteomics studies directed towards biomarker discovery intended for use in diagnostics, prognostics and even in theranostics. The result of these extensive efforts is a long list of potential biomarkers, very few of which have led to clinical utility. Why have so many potential biomarkers failed validation? Herein, we address certain issues encountered, which complicate biomarker discovery efforts originating from plasma. The advantages of stabilizing the sample at collection by the addition of protease inhibitors are discussed. The principles of free-flow electrophoresis (FFE) separation are provided together with examples applying to various studies. Finally, particular attention is given to plasma or serum analysis using multidimensional separation strategies into which the FFE is incorporated. The advantages of using FFE separation in these workflows are discussed.

Centrifugal separator devices, systems and related methods

DOEpatents

Meikrantz, David H [Idaho Falls, ID; Law, Jack D [Pocatello, ID; Garn, Troy G [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Macaluso, Lawrence L [Carson City, NV

2012-03-20

Centrifugal separator devices, systems and related methods are described. More particularly, fluid transfer connections for a centrifugal separator system having support assemblies with a movable member coupled to a connection tube and coupled to a fixed member, such that the movable member is constrained to movement along a fixed path relative to the fixed member are described. Also, centrifugal separator systems including such fluid transfer connections are described. Additionally, methods of installing, removing and/or replacing centrifugal separators from centrifugal separator systems are described.

Union Dissolution and Mobility: Who Moves from the Family Home after Separation?

ERIC Educational Resources Information Center

Mulder, Clara H.; Wagner, Michael

2010-01-01

We investigate which partner of a 2-gender couple moves out after separation. We test hypotheses on the impact of differences between the partners in the costs of moving out and resources, using data from the Divorce in the Netherlands survey (N = 1,537 ex-couples who separated between 1972 and 1998). Ex-partners initiating the separation were…

Financial Arrangements and Relationship Quality in Low-Income Couples

ERIC Educational Resources Information Center

Addo, Fenaba R.; Sassler, Sharon

2010-01-01

This study explored the association between household financial arrangements and relationship quality using a representative sample of low-income couples with children. We detailed the banking arrangements couples utilize, assessed which factors relate to holding a joint account versus joint and separate, only separate, or no account, and analyzed…

Rapid determination of thermodynamic parameters from one-dimensional programmed-temperature gas chromatography for use in retention time prediction in comprehensive multidimensional chromatography.

PubMed

McGinitie, Teague M; Ebrahimi-Najafabadi, Heshmatollah; Harynuk, James J

2014-01-17

A new method for estimating the thermodynamic parameters of ΔH(T0), ΔS(T0), and ΔCP for use in thermodynamic modeling of GC×GC separations has been developed. The method is an alternative to the traditional isothermal separations required to fit a three-parameter thermodynamic model to retention data. Herein, a non-linear optimization technique is used to estimate the parameters from a series of temperature-programmed separations using the Nelder-Mead simplex algorithm. With this method, the time required to obtain estimates of thermodynamic parameters a series of analytes is significantly reduced. This new method allows for precise predictions of retention time with the average error being only 0.2s for 1D separations. Predictions for GC×GC separations were also in agreement with experimental measurements; having an average relative error of 0.37% for (1)tr and 2.1% for (2)tr. Copyright © 2013 Elsevier B.V. All rights reserved.

A computational approach for coupled 1D and 2D/3D CFD modelling of pulse Tube cryocoolers

NASA Astrophysics Data System (ADS)

Fang, T.; Spoor, P. S.; Ghiaasiaan, S. M.

2017-12-01

The physics behind Stirling-type cryocoolers are complicated. One dimensional (1D) simulation tools offer limited details and accuracy, in particular for cryocoolers that have non-linear configurations. Multi-dimensional Computational Fluid Dynamic (CFD) methods are useful but are computationally expensive in simulating cyrocooler systems in their entirety. In view of the fact that some components of a cryocooler, e.g., inertance tubes and compliance tanks, can be modelled as 1D components with little loss of critical information, a 1D-2D/3D coupled model was developed. Accordingly, one-dimensional - like components are represented by specifically developed routines. These routines can be coupled to CFD codes and provide boundary conditions for 2D/3D CFD simulations. The developed coupled model, while preserving sufficient flow field details, is two orders of magnitude faster than equivalent 2D/3D CFD models. The predictions show good agreement with experimental data and 2D/3D CFD model.

A high-order relativistic two-fluid electrodynamic scheme with consistent reconstruction of electromagnetic fields and a multidimensional Riemann solver for electromagnetism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balsara, Dinshaw S., E-mail: dbalsara@nd.edu; Amano, Takanobu, E-mail: amano@eps.s.u-tokyo.ac.jp; Garain, Sudip, E-mail: sgarain@nd.edu

In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement current in the ideal, classical magnetohydrodynamic limit, when the flows become relativistic this approximation is less than absolutely well-justified. In such a situation, it is more natural to consider a positively charged fluid made up of positrons or protons interacting with a negatively charged fluid made up of electrons. The two fluids interact collectively with the full set of Maxwell's equations. As a result, a solution strategy for that coupled system of equationsmore » is sought and found here. Our strategy extends to higher orders, providing increasing accuracy. The primary variables in the Maxwell solver are taken to be the facially-collocated components of the electric and magnetic fields. Consistent with such a collocation, three important innovations are reported here. The first two pertain to the Maxwell solver. In our first innovation, the magnetic field within each zone is reconstructed in a divergence-free fashion while the electric field within each zone is reconstructed in a form that is consistent with Gauss' law. In our second innovation, a multidimensionally upwinded strategy is presented which ensures that the magnetic field can be updated via a discrete interpretation of Faraday's law and the electric field can be updated via a discrete interpretation of the generalized Ampere's law. This multidimensional upwinding is achieved via a multidimensional Riemann solver. The multidimensional Riemann solver automatically provides edge-centered electric field components for the Stokes law-based update of the magnetic field. It also provides edge-centered magnetic field components for the Stokes law-based update of the electric field. The update strategy ensures that the electric field is always consistent with Gauss' law and the magnetic field is always divergence-free. This collocation also ensures that electromagnetic radiation that is propagating in a vacuum has both electric and magnetic fields that are exactly divergence-free. Coupled relativistic fluid dynamic equations are solved for the positively and negatively charged fluids. The fluids' numerical fluxes also provide a self-consistent current density for the update of the electric field. Our reconstruction strategy ensures that fluid velocities always remain sub-luminal. Our third innovation consists of an efficient design for several popular IMEX schemes so that they provide strong coupling between the finite-volume-based fluid solver and the electromagnetic fields at high order. This innovation makes it possible to efficiently utilize high order IMEX time update methods for stiff source terms in the update of high order finite-volume methods for hyperbolic conservation laws. We also show that this very general innovation should extend seamlessly to Runge–Kutta discontinuous Galerkin methods. The IMEX schemes enable us to use large CFL numbers even in the presence of stiff source terms. Several accuracy analyses are presented showing that our method meets its design accuracy in the MHD limit as well as in the limit of electromagnetic wave propagation. Several stringent test problems are also presented. We also present a relativistic version of the GEM problem, which shows that our algorithm can successfully adapt to challenging problems in high energy astrophysics.« less

A high-order relativistic two-fluid electrodynamic scheme with consistent reconstruction of electromagnetic fields and a multidimensional Riemann solver for electromagnetism

NASA Astrophysics Data System (ADS)

Balsara, Dinshaw S.; Amano, Takanobu; Garain, Sudip; Kim, Jinho

2016-08-01

In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement current in the ideal, classical magnetohydrodynamic limit, when the flows become relativistic this approximation is less than absolutely well-justified. In such a situation, it is more natural to consider a positively charged fluid made up of positrons or protons interacting with a negatively charged fluid made up of electrons. The two fluids interact collectively with the full set of Maxwell's equations. As a result, a solution strategy for that coupled system of equations is sought and found here. Our strategy extends to higher orders, providing increasing accuracy. The primary variables in the Maxwell solver are taken to be the facially-collocated components of the electric and magnetic fields. Consistent with such a collocation, three important innovations are reported here. The first two pertain to the Maxwell solver. In our first innovation, the magnetic field within each zone is reconstructed in a divergence-free fashion while the electric field within each zone is reconstructed in a form that is consistent with Gauss' law. In our second innovation, a multidimensionally upwinded strategy is presented which ensures that the magnetic field can be updated via a discrete interpretation of Faraday's law and the electric field can be updated via a discrete interpretation of the generalized Ampere's law. This multidimensional upwinding is achieved via a multidimensional Riemann solver. The multidimensional Riemann solver automatically provides edge-centered electric field components for the Stokes law-based update of the magnetic field. It also provides edge-centered magnetic field components for the Stokes law-based update of the electric field. The update strategy ensures that the electric field is always consistent with Gauss' law and the magnetic field is always divergence-free. This collocation also ensures that electromagnetic radiation that is propagating in a vacuum has both electric and magnetic fields that are exactly divergence-free. Coupled relativistic fluid dynamic equations are solved for the positively and negatively charged fluids. The fluids' numerical fluxes also provide a self-consistent current density for the update of the electric field. Our reconstruction strategy ensures that fluid velocities always remain sub-luminal. Our third innovation consists of an efficient design for several popular IMEX schemes so that they provide strong coupling between the finite-volume-based fluid solver and the electromagnetic fields at high order. This innovation makes it possible to efficiently utilize high order IMEX time update methods for stiff source terms in the update of high order finite-volume methods for hyperbolic conservation laws. We also show that this very general innovation should extend seamlessly to Runge-Kutta discontinuous Galerkin methods. The IMEX schemes enable us to use large CFL numbers even in the presence of stiff source terms. Several accuracy analyses are presented showing that our method meets its design accuracy in the MHD limit as well as in the limit of electromagnetic wave propagation. Several stringent test problems are also presented. We also present a relativistic version of the GEM problem, which shows that our algorithm can successfully adapt to challenging problems in high energy astrophysics.

Development of a Multidimensional Functional Health Scale for Older Adults in China.

PubMed

Mao, Fanzhen; Han, Yaofeng; Chen, Junze; Chen, Wei; Yuan, Manqiong; Alicia Hong, Y; Fang, Ya

2016-05-01

A first step to achieve successful aging is assessing functional wellbeing of older adults. This study reports the development of a culturally appropriate brief scale (the Multidimensional Functional Health Scale for Chinese Elderly, MFHSCE) to assess the functional health of Chinese elderly. Through systematic literature review, Delphi method, cultural adaptation, synthetic statistical item selection, Cronbach's alpha and confirmatory factor analysis, we conducted development of item pool, two rounds of item selection, and psychometric evaluation. Synthetic statistical item selection and psychometric evaluation was processed among 539 and 2032 older adults, separately. The MFHSCE consists of 30 items, covering activities of daily living, social relationships, physical health, mental health, cognitive function, and economic resources. The Cronbach's alpha was 0.92, and the comparative fit index was 0.917. The MFHSCE has good internal consistency and construct validity; it is also concise and easy to use in general practice, especially in communities in China.

Measuring geographic segregation: a graph-based approach

NASA Astrophysics Data System (ADS)

Hong, Seong-Yun; Sadahiro, Yukio

2014-04-01

Residential segregation is a multidimensional phenomenon that encompasses several conceptually distinct aspects of geographical separation between populations. While various indices have been developed as a response to different definitions of segregation, the reliance on such single-figure indices could oversimplify the complex, multidimensional phenomena. In this regard, this paper suggests an alternative graph-based approach that provides more detailed information than simple indices: The concentration profile graphically conveys information about how evenly a population group is distributed over the study region, and the spatial proximity profile depicts the degree of clustering across different threshold levels. These graphs can also be summarized into single numbers for comparative purposes, but the interpretation can be more accurate by inspecting the additional information. To demonstrate the use of these methods, the residential patterns of three major ethnic groups in Auckland, namely Māori, Pacific peoples, and Asians, are examined using the 2006 census data.

Explicit and implicit compact high-resolution shock-capturing methods for multidimensional Euler equations 1: Formulation

NASA Technical Reports Server (NTRS)

Yee, H. C.

1995-01-01

Two classes of explicit compact high-resolution shock-capturing methods for the multidimensional compressible Euler equations for fluid dynamics are constructed. Some of these schemes can be fourth-order accurate away from discontinuities. For the semi-discrete case their shock-capturing properties are of the total variation diminishing (TVD), total variation bounded (TVB), total variation diminishing in the mean (TVDM), essentially nonoscillatory (ENO), or positive type of scheme for 1-D scalar hyperbolic conservation laws and are positive schemes in more than one dimension. These fourth-order schemes require the same grid stencil as their second-order non-compact cousins. One class does not require the standard matrix inversion or a special numerical boundary condition treatment associated with typical compact schemes. Due to the construction, these schemes can be viewed as approximations to genuinely multidimensional schemes in the sense that they might produce less distortion in spherical type shocks and are more accurate in vortex type flows than schemes based purely on one-dimensional extensions. However, one class has a more desirable high-resolution shock-capturing property and a smaller operation count in 3-D than the other class. The extension of these schemes to coupled nonlinear systems can be accomplished using the Roe approximate Riemann solver, the generalized Steger and Warming flux-vector splitting or the van Leer type flux-vector splitting. Modification to existing high-resolution second- or third-order non-compact shock-capturing computer codes is minimal. High-resolution shock-capturing properties can also be achieved via a variant of the second-order Lax-Friedrichs numerical flux without the use of Riemann solvers for coupled nonlinear systems with comparable operations count to their classical shock-capturing counterparts. The simplest extension to viscous flows can be achieved by using the standard fourth-order compact or non-compact formula for the viscous terms.

Beyond the continuum: a multi-dimensional phase space for neutral-niche community assembly.

PubMed

Latombe, Guillaume; Hui, Cang; McGeoch, Melodie A

2015-12-22

Neutral and niche processes are generally considered to interact in natural communities along a continuum, exhibiting community patterns bounded by pure neutral and pure niche processes. The continuum concept uses niche separation, an attribute of the community, to test the hypothesis that communities are bounded by pure niche or pure neutral conditions. It does not accommodate interactions via feedback between processes and the environment. By contrast, we introduce the Community Assembly Phase Space (CAPS), a multi-dimensional space that uses community processes (such as dispersal and niche selection) to define the limiting neutral and niche conditions and to test the continuum hypothesis. We compare the outputs of modelled communities in a heterogeneous landscape, assembled by pure neutral, pure niche and composite processes. Differences in patterns under different combinations of processes in CAPS reveal hidden complexity in neutral-niche community dynamics. The neutral-niche continuum only holds for strong dispersal limitation and niche separation. For weaker dispersal limitation and niche separation, neutral and niche processes amplify each other via feedback with the environment. This generates patterns that lie well beyond those predicted by a continuum. Inferences drawn from patterns about community assembly processes can therefore be misguided when based on the continuum perspective. CAPS also demonstrates the complementary information value of different patterns for inferring community processes and captures the complexity of community assembly. It provides a general tool for studying the processes structuring communities and can be applied to address a range of questions in community and metacommunity ecology. © 2015 The Author(s).

Beyond the continuum: a multi-dimensional phase space for neutral–niche community assembly

PubMed Central

Latombe, Guillaume; McGeoch, Melodie A.

2015-01-01

Neutral and niche processes are generally considered to interact in natural communities along a continuum, exhibiting community patterns bounded by pure neutral and pure niche processes. The continuum concept uses niche separation, an attribute of the community, to test the hypothesis that communities are bounded by pure niche or pure neutral conditions. It does not accommodate interactions via feedback between processes and the environment. By contrast, we introduce the Community Assembly Phase Space (CAPS), a multi-dimensional space that uses community processes (such as dispersal and niche selection) to define the limiting neutral and niche conditions and to test the continuum hypothesis. We compare the outputs of modelled communities in a heterogeneous landscape, assembled by pure neutral, pure niche and composite processes. Differences in patterns under different combinations of processes in CAPS reveal hidden complexity in neutral–niche community dynamics. The neutral–niche continuum only holds for strong dispersal limitation and niche separation. For weaker dispersal limitation and niche separation, neutral and niche processes amplify each other via feedback with the environment. This generates patterns that lie well beyond those predicted by a continuum. Inferences drawn from patterns about community assembly processes can therefore be misguided when based on the continuum perspective. CAPS also demonstrates the complementary information value of different patterns for inferring community processes and captures the complexity of community assembly. It provides a general tool for studying the processes structuring communities and can be applied to address a range of questions in community and metacommunity ecology. PMID:26702047

Enjoying mathematics or feeling competent in mathematics? Reciprocal effects on mathematics achievement and perceived math effort expenditure.

PubMed

Pinxten, Maarten; Marsh, Herbert W; De Fraine, Bieke; Van Den Noortgate, Wim; Van Damme, Jan

2014-03-01

The multidimensionality of the academic self-concept in terms of domain specificity has been well established in previous studies, whereas its multidimensionality in terms of motivational functions (the so-called affect-competence separation) needs further examination. This study aims at exploring differential effects of enjoyment and competence beliefs on two external validity criteria in the field of mathematics. Data analysed in this study were part of a large-scale longitudinal research project. Following a five-wave design, math enjoyment, math competence beliefs, math achievement, and perceived math effort expenditure measures were repeatedly collected from a cohort of 4,724 pupils in Grades 3-7. Confirmatory factor analysis (CFA) was used to test the internal factor structure of the math self-concept. Additionally, a series of nested models was tested using structural equation modelling to examine longitudinal reciprocal interrelations between math competence beliefs and math enjoyment on the one hand and math achievement and perceived math effort expenditure on the other. Our results showed that CFA models with separate factors for math enjoyment and math competence beliefs fit the data substantially better than models without it. Furthermore, differential relationships between both constructs and the two educational outcomes were observed. Math competence beliefs had positive effects on math achievement and negative effects on perceived math effort expenditure. Math enjoyment had (mild) positive effects on subsequent perceived effort expenditure and math competence beliefs. This study provides further support for the affect-competence separation. Theoretical issues regarding adequate conceptualization and practical consequences for practitioners are discussed. © 2013 The British Psychological Society.

Bridging Multidimensional Models of Ethnic-Racial and Gender Identity Among Ethnically Diverse Emerging Adults.

PubMed

Wilson, Antoinette R; Leaper, Campbell

2016-08-01

The purpose of this study was to integrate and validate a multidimensional model of ethnic-racial identity and gender identity borrowing constructs and measures based on social identity and gender identity theories. Participants included 662 emerging adults (M age  = 19.86 years; 75 % female) who self-identified either as Asian American, Latino/a, or White European American. We assessed the following facets separately for ethnic-racial identity and gender identity: centrality, in-group affect, in-group ties, self-perceived typicality, and felt conformity pressure. Within each identity domain (gender or ethnicity/race), the five dimensions generally indicated small-to-moderate correlations with one another. Also, correlations between domains for each dimension (e.g., gender typicality and ethnic-racial typicality) were mostly moderate in magnitude. We also noted some group variations based on participants' ethnicity/race and gender in how strongly particular dimensions were associated with self-esteem. Finally, participants who scored positively on identity dimensions for both gender and ethnic-racial domains indicated higher self-esteem than those who scored high in only one domain or low in both domains. We recommend the application of multidimensional models to study social identities in multiple domains as they may relate to various outcomes during development.

Multidimensional High-Resolution Gas Chromatographic Investigations of Hydrocarbon Fuels and Various Turbine Engine Fuel Precursors.

DTIC Science & Technology

1985-08-01

time were spurious transits observed during the recording of the chromatographic output data. *Packaged gas purification filters supplied by Alltech ... Alltech ) that were needed for these unusual installations. When the column diameters were small and of comparable size, the assembly attach- ments at...into an MDGC system has definite advantages as separations can be made faster and with greater detectability. However, specific precautions must be

Global limits and interference patterns in dark matter direct detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catena, Riccardo; Gondolo, Paolo

2015-08-13

We compare the general effective theory of one-body dark matter nucleon interactions to current direct detection experiments in a global multidimensional statistical analysis. We derive exclusion limits on the 28 isoscalar and isovector coupling constants of the theory, and show that current data place interesting constraints on dark matter-nucleon interaction operators usually neglected in this context. We characterize the interference patterns that can arise in dark matter direct detection from pairs of dark matter-nucleon interaction operators, or from isoscalar and isovector components of the same operator. We find that commonly neglected destructive interference effects weaken standard direct detection exclusion limitsmore » by up to one order of magnitude in the coupling constants.« less

Global limits and interference patterns in dark matter direct detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catena, Riccardo; Gondolo, Paolo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: paolo.gondolo@utah.edu

2015-08-01

We compare the general effective theory of one-body dark matter nucleon interactions to current direct detection experiments in a global multidimensional statistical analysis. We derive exclusion limits on the 28 isoscalar and isovector coupling constants of the theory, and show that current data place interesting constraints on dark matter-nucleon interaction operators usually neglected in this context. We characterize the interference patterns that can arise in dark matter direct detection from pairs of dark matter-nucleon interaction operators, or from isoscalar and isovector components of the same operator. We find that commonly neglected destructive interference effects weaken standard direct detection exclusion limitsmore » by up to one order of magnitude in the coupling constants.« less

Protein Stable Isotope Fingerprinting (P-SIF): Multidimensional Protein Chromatography Coupled to Stable Isotope-Ratio Mass Spectrometry

NASA Astrophysics Data System (ADS)

Pearson, A.; Bovee, R. J.; Mohr, W.; Tang, T.

2012-12-01

As metagenomics increases our insight into microbial community diversity and metabolic potential, new approaches are required to determine the biogeochemical expression of this potential within ecosystems. Because stable isotopic analysis of the major bioactive elements (C, N) has been used historically to map flows of substrates and energy among macroscopic food webs, similar principles may apply to microbes. To address this challenge, we have developed a new analytical approach called Protein Stable Isotope Fingerprinting (P-SIF). P-SIF generates natural stable isotopic fingerprints of microbial individual or community proteomes. The main advantage of P-SIF is the potential to bridge the gap between diversity and function, thereby providing a window into the "black box" of environmental microbiology and helping to decipher the roles of uncultivated species. Our method implements a three-way, orthogonal scheme to separate mixtures of whole proteins into subfractions dominated by single or closely-related proteins. Protein extracts first are isoelectrically focused in a gel-free technique that yields 12 fractions separated over a gradient of pH 3-10. Each fraction then is separated by size-exclusion chromatography into 20 pools, ranging from >100kD to ~10kD. Finally, each of these pools is subjected to HPLC and collected in 40 time-slices based on protein hydrophobicity. Theoretical calculation reveals that the true chromatographic resolution of the total scheme is 5000, somewhat less than the 9600 resulting fractions. High-yielding fractions are subjected to δ13C analysis by spooling-wire microcombustion irMS (SWiM-irMS) optimized for samples containing 1-5 nmol carbon. Here we will present the method, results for a variety of pure cultures, and preliminary data for a sample of mixed environmental proteins. The data show the promise of this method for unraveling the metabolic complexity hidden within microbial communities.

Solid-state NMR investigations of cellulose structure and interactions with matrix polysaccharides in plant primary cell walls.

PubMed

Wang, Tuo; Hong, Mei

2016-01-01

Until recently, the 3D architecture of plant cell walls was poorly understood due to the lack of high-resolution techniques for characterizing the molecular structure, dynamics, and intermolecular interactions of the wall polysaccharides in these insoluble biomolecular mixtures. We introduced multidimensional solid-state NMR (SSNMR) spectroscopy, coupled with (13)C labelling of whole plants, to determine the spatial arrangements of macromolecules in near-native plant cell walls. Here we review key evidence from 2D and 3D correlation NMR spectra that show relatively few cellulose-hemicellulose cross peaks but many cellulose-pectin cross peaks, indicating that cellulose microfibrils are not extensively coated by hemicellulose and all three major polysaccharides exist in a single network rather than two separate networks as previously proposed. The number of glucan chains in the primary-wall cellulose microfibrils has been under active debate recently. We show detailed analysis of quantitative (13)C SSNMR spectra of cellulose in various wild-type (WT) and mutant Arabidopsis and Brachypodium primary cell walls, which consistently indicate that primary-wall cellulose microfibrils contain at least 24 glucan chains. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Integrated modeling/analyses of thermal-shock effects in SNS targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taleyarkhan, R.P.; Haines, J.

1996-06-01

In a spallation neutron source (SNS), extremely rapid energy pulses are introduced in target materials such as mercury, lead, tungsten, uranium, etc. Shock phenomena in such systems may possibly lead to structural material damage beyond the design basis. As expected, the progression of shock waves and interaction with surrounding materials for liquid targets can be quite different from that in solid targets. The purpose of this paper is to describe ORNL`s modeling framework for `integrated` assessment of thermal-shock issues in liquid and solid target designs. This modeling framework is being developed based upon expertise developed from past reactor safety studies,more » especially those related to the Advanced Neutron Source (ANS) Project. Unlike previous separate-effects modeling approaches employed (for evaluating target behavior when subjected to thermal shocks), the present approach treats the overall problem in a coupled manner using state-of-the-art equations of state for materials of interest (viz., mercury, tungsten and uranium). That is, the modeling framework simultaneously accounts for localized (and distributed) compression pressure pulse generation due to transient heat deposition, the transport of this shock wave outwards, interaction with surrounding boundaries, feedback to mercury from structures, multi-dimensional reflection patterns & stress induced (possible) breakup or fracture.« less

Proton-Based Ultrafast Magic Angle Spinning Solid-State NMR Spectroscopy.

PubMed

Zhang, Rongchun; Mroue, Kamal H; Ramamoorthy, Ayyalusamy

2017-04-18

Protons are vastly abundant in a wide range of exciting macromolecules and thus can be a powerful probe to investigate the structure and dynamics at atomic resolution using solid-state NMR (ssNMR) spectroscopy. Unfortunately, the high signal sensitivity, afforded by the high natural-abundance and high gyromagnetic ratio of protons, is greatly compromised by severe line broadening due to the very strong 1 H- 1 H dipolar couplings. As a result, protons are rarely used, in spite of the desperate need for enhancing the sensitivity of ssNMR to study a variety of systems that are not amenable for high resolution investigation using other techniques including X-ray crystallography, cryo-electron microscopy, and solution NMR spectroscopy. Thanks to the remarkable improvement in proton spectral resolution afforded by the significant advances in magic-angle-spinning (MAS) probe technology, 1 H ssNMR spectroscopy has recently attracted considerable attention in the structural and dynamics studies of various molecular systems. However, it still remains a challenge to obtain narrow 1 H spectral lines, especially from proteins, without resorting to deuteration. In this Account, we review recent proton-based ssNMR strategies that have been developed in our laboratory to further improve proton spectral resolution without resorting to chemical deuteration for the purposes of gaining atomistic-level insights into molecular structures of various crystalline solid systems, using small molecules and peptides as illustrative examples. The proton spectral resolution enhancement afforded by the ultrafast MAS frequencies up to 120 kHz is initially discussed, followed by a description of an ensemble of multidimensional NMR pulse sequences, all based on proton detection, that have been developed to obtain in-depth information from dipolar couplings and chemical shift anisotropy (CSA). Simple single channel multidimensional proton NMR experiments could be performed to probe the proximity of protons for structure determination using 1 H- 1 H dipolar couplings and to evaluate the changes in chemical environments as well as the relative orientation to the external magnetic field using proton CSA. Due to the boost in signal sensitivity enabled by proton detection under ultrafast MAS, by virtue of high proton natural abundance and gyromagnetic ratio, proton-detected multidimensional experiments involving low-γ nuclei can now be accomplished within a reasonable time, while the higher dimension also offers additional resolution enhancement. In addition, the application of proton-based ssNMR spectroscopy under ultrafast MAS in various challenging and crystalline systems is also presented. Finally, we briefly discuss the limitations and challenges pertaining to proton-based ssNMR spectroscopy under ultrafast MAS conditions, such as the presence of high-order dipolar couplings, friction-induced sample heating, and limited sample volume. Although there are still a number of challenges that must be circumvented by further developments in radio frequency pulse sequences, MAS probe technology and approaches to prepare NMR-friendly samples, proton-based ssNMR has already gained much popularity in various research domains, especially in proteins where uniform or site-selective deuteration can be relatively easily achieved. In addition, implementation of the recently developed fast data acquisition approaches would also enable further developments in the design and applications of proton-based ultrafast MAS multidimensional ssNMR techniques.

Integrated Multi-process Microfluidic Systems for Automating Analysis

PubMed Central

Yang, Weichun; Woolley, Adam T.

2010-01-01

Microfluidic technologies have been applied extensively in rapid sample analysis. Some current challenges for standard microfluidic systems are relatively high detection limits, and reduced resolving power and peak capacity compared to conventional approaches. The integration of multiple functions and components onto a single platform can overcome these separation and detection limitations of microfluidics. Multiplexed systems can greatly increase peak capacity in multidimensional separations and can increase sample throughput by analyzing many samples simultaneously. On-chip sample preparation, including labeling, preconcentration, cleanup and amplification, can all serve to speed up and automate processes in integrated microfluidic systems. This paper summarizes advances in integrated multi-process microfluidic systems for automated analysis, their benefits and areas for needed improvement. PMID:20514343

Separation of actinides using capillary extraction chromatography-inductively coupled plasma mass spectrometry.

PubMed

Peterson, Dominic S; Montoya, Velma M

2009-08-01

Trace levels of actinides have been separated on capillary extraction chromatography columns. Detection of the actinides was achieved using an inductively coupled plasma mass spectrometer, which was coupled with the extraction chromatography system. In this study, we compare 30-cm long, 4.6 mm i.d. columns to capillary columns (750 microm i.d.) with lengths from 30 cm up to 150 cm. The columns that were tested were packed with TRU resin. We were able to separate a mixture of five actinides ((232)Th, (238)U, (237)Np, (239)Pu, and (241)Am). This work has application to rapid bioassay as well as automated separations of actinide materials.

A support vector machine based test for incongruence between sets of trees in tree space

PubMed Central

2012-01-01

Background The increased use of multi-locus data sets for phylogenetic reconstruction has increased the need to determine whether a set of gene trees significantly deviate from the phylogenetic patterns of other genes. Such unusual gene trees may have been influenced by other evolutionary processes such as selection, gene duplication, or horizontal gene transfer. Results Motivated by this problem we propose a nonparametric goodness-of-fit test for two empirical distributions of gene trees, and we developed the software GeneOut to estimate a p-value for the test. Our approach maps trees into a multi-dimensional vector space and then applies support vector machines (SVMs) to measure the separation between two sets of pre-defined trees. We use a permutation test to assess the significance of the SVM separation. To demonstrate the performance of GeneOut, we applied it to the comparison of gene trees simulated within different species trees across a range of species tree depths. Applied directly to sets of simulated gene trees with large sample sizes, GeneOut was able to detect very small differences between two set of gene trees generated under different species trees. Our statistical test can also include tree reconstruction into its test framework through a variety of phylogenetic optimality criteria. When applied to DNA sequence data simulated from different sets of gene trees, results in the form of receiver operating characteristic (ROC) curves indicated that GeneOut performed well in the detection of differences between sets of trees with different distributions in a multi-dimensional space. Furthermore, it controlled false positive and false negative rates very well, indicating a high degree of accuracy. Conclusions The non-parametric nature of our statistical test provides fast and efficient analyses, and makes it an applicable test for any scenario where evolutionary or other factors can lead to trees with different multi-dimensional distributions. The software GeneOut is freely available under the GNU public license. PMID:22909268

Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balke, Nina; Kalinin, Sergei V.; Jesse, Stephen

Kelvin probe force microscopy (KPFM) has provided deep insights into the role local electronic, ionic and electrochemical processes play on the global functionality of materials and devices, even down to the atomic scale. Conventional KPFM utilizes heterodyne detection and bias feedback to measure the contact potential difference (CPD) between tip and sample. This measurement paradigm, however, permits only partial recovery of the information encoded in bias- and time-dependent electrostatic interactions between the tip and sample and effectively down-samples the cantilever response to a single measurement of CPD per pixel. This level of detail is insufficient for electroactive materials, devices, ormore » solid-liquid interfaces, where non-linear dielectrics are present or spurious electrostatic events are possible. Here, we simulate and experimentally validate a novel approach for spatially resolved KPFM capable of a full information transfer of the dynamic electric processes occurring between tip and sample. General acquisition mode, or G-Mode, adopts a big data approach utilising high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates (> 4 MHz), providing a permanent record of the tip trajectory. We develop a range of methodologies for analysing the resultant large multidimensional datasets involving classical, physics-based and information-based approaches. Physics-based analysis of G-Mode KPFM data recovers the parabolic bias dependence of the electrostatic force for each cycle of the excitation voltage, leading to a multidimensional dataset containing spatial and temporal dependence of the CPD and capacitance channels. We use multivariate statistical methods to reduce data volume and separate the complex multidimensional data sets into statistically significant components that can then be mapped onto separate physical mechanisms. Overall, G-Mode KPFM offers a new paradigm to study dynamic electric phenomena in electroactive interfaces as well as offer a promising approach to extend KPFM to solid-liquid interfaces.« less

Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space

DOE PAGES

Balke, Nina; Kalinin, Sergei V.; Jesse, Stephen; ...

2016-08-12

Kelvin probe force microscopy (KPFM) has provided deep insights into the role local electronic, ionic and electrochemical processes play on the global functionality of materials and devices, even down to the atomic scale. Conventional KPFM utilizes heterodyne detection and bias feedback to measure the contact potential difference (CPD) between tip and sample. This measurement paradigm, however, permits only partial recovery of the information encoded in bias- and time-dependent electrostatic interactions between the tip and sample and effectively down-samples the cantilever response to a single measurement of CPD per pixel. This level of detail is insufficient for electroactive materials, devices, ormore » solid-liquid interfaces, where non-linear dielectrics are present or spurious electrostatic events are possible. Here, we simulate and experimentally validate a novel approach for spatially resolved KPFM capable of a full information transfer of the dynamic electric processes occurring between tip and sample. General acquisition mode, or G-Mode, adopts a big data approach utilising high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates (> 4 MHz), providing a permanent record of the tip trajectory. We develop a range of methodologies for analysing the resultant large multidimensional datasets involving classical, physics-based and information-based approaches. Physics-based analysis of G-Mode KPFM data recovers the parabolic bias dependence of the electrostatic force for each cycle of the excitation voltage, leading to a multidimensional dataset containing spatial and temporal dependence of the CPD and capacitance channels. We use multivariate statistical methods to reduce data volume and separate the complex multidimensional data sets into statistically significant components that can then be mapped onto separate physical mechanisms. Overall, G-Mode KPFM offers a new paradigm to study dynamic electric phenomena in electroactive interfaces as well as offer a promising approach to extend KPFM to solid-liquid interfaces.« less

The effects of inter-cavity separation on optical coupling in dielectric bispheres.

PubMed

Ashili, Shashanka P; Astratov, Vasily N; Sykes, E Charles H

2006-10-02

The optical coupling between two size-mismatched spheres was studied by using one sphere as a local source of light with whispering gallery modes (WGMs) and detecting the intensity of the light scattered by a second sphere playing the part of a receiver of electromagnetic energy. We developed techniques to control inter-cavity gap sizes between microspheres with ~30nm accuracy. We demonstrate high efficiencies (up to 0.2-0.3) of coupling between two separated cavities with strongly detuned eigenstates. At small separations (<1 microm) between the spheres, the mechanism of coupling is interpreted in terms of the Fano resonance between discrete level (true WGMs excited in a source sphere) and a continuum of "quasi"-WGMs with distorted shape which can be induced in the receiving sphere. At larger separations the spectra detected from the receiving sphere originate from scattering of the radiative modes.

Hybrid finite element and Brownian dynamics method for diffusion-controlled reactions.

PubMed

Bauler, Patricia; Huber, Gary A; McCammon, J Andrew

2012-04-28

Diffusion is often the rate determining step in many biological processes. Currently, the two main computational methods for studying diffusion are stochastic methods, such as Brownian dynamics, and continuum methods, such as the finite element method. This paper proposes a new hybrid diffusion method that couples the strengths of each of these two methods. The method is derived for a general multidimensional system, and is presented using a basic test case for 1D linear and radially symmetric diffusion systems.

Gravitational wave-Gauge field oscillations

NASA Astrophysics Data System (ADS)

Caldwell, R. R.; Devulder, C.; Maksimova, N. A.

2016-09-01

Gravitational waves propagating through a stationary gauge field transform into gauge field waves and back again. When multiple families of flavor-space locked gauge fields are present, the gravitational and gauge field waves exhibit novel dynamics. At high frequencies, the system behaves like coupled oscillators in which the gravitational wave is the central pacemaker. Due to energy conservation and exchange among the oscillators, the wave amplitudes lie on a multidimensional sphere, reminiscent of neutrino flavor oscillations. This phenomenon has implications for cosmological scenarios based on flavor-space locked gauge fields.

Centrifugal separators and related devices and methods

DOEpatents

Meikrantz, David H [Idaho Falls, ID; Law, Jack D [Pocatello, ID; Garn, Troy G [Idaho Falls, ID; Macaluso, Lawrence L [Carson City, NV; Todd, Terry A [Aberdeen, ID

2012-03-06

Centrifugal separators and related methods and devices are described. More particularly, centrifugal separators comprising a first fluid supply fitting configured to deliver fluid into a longitudinal fluid passage of a rotor shaft and a second fluid supply fitting sized and configured to sealingly couple with the first fluid supply fitting are described. Also, centrifugal separator systems comprising a manifold having a drain fitting and a cleaning fluid supply fitting are described, wherein the manifold is coupled to a movable member of a support assembly. Additionally, methods of cleaning centrifugal separators are described.

Toward highly sensitive surface-enhanced Raman scattering: the design of a 3D hybrid system with monolayer graphene sandwiched between silver nanohole arrays and gold nanoparticles.

PubMed

Zhao, Yuan; Yang, Dong; Li, Xiyu; Liu, Yu; Hu, Xiang; Zhou, Dianfa; Lu, Yalin

2017-01-19

We report a novel graphene-metal hybrid system by introducing monolayer graphene between gold nanoparticles (Au NPs) and silver nanohole (Ag NH) arrays. The design incorporates three key advantages to promote the surface-enhanced Raman scattering (SERS) sensing capacity: (i) making full use of the single-atomic feature of graphene for generating uniform sub-nanometer spaces; (ii) maintaining the bottom layer of Ag nanoarrays with an ordered manner for facilitating the transfer of graphene films and assembly of the top layer of Au NPs; (iii) integrating the advantages of the strong plasmonic effect of Ag, the chemical stability of Au, as well as the mechanical flexibility and biological compatibility of graphene. In this configuration, the plasmonic properties can be fine-tuned by separately optimizing the horizontal or vertical gaps between the metal NPs. Exactly, sub-20 nm spaces between the horizontally patterned Ag tips constructed by adjacent Ag NHs, and sub-nanometer scale graphene gaps between the vertically distributed Au NP-Ag NH have been achieved. Finite element numerical simulations demonstrate that the multi-dimensional plasmonic couplings (including the Au NP-Au NP, Au NP-Ag NH and Ag NH-Ag NH couplings) promote for the hybrid platform an electric field enhancement up to 137 times. Impressively, the as-prepared 3D Au NP-graphene-Ag NH array hybrid structure manifests ultrahigh SERS sensitivity with a detection limit of 10 -13 M for R6G molecules, as well as good reproducibility and stability. This work represents a step towards high-performance SERS substrate fabrication, and opens up a new route for graphene-plasmonic hybrids in SERS applications.

Changing sex risk behaviors, gender norms, and relationship dynamics among couples in Cape Town, South Africa: Efficacy of an intervention on the dyad.

PubMed

Speizer, Ilene S; Zule, William A; Carney, Tara; Browne, Felicia A; Ndirangu, Jacqueline; Wechsberg, Wendee M

2018-05-18

South Africa continues to experience new HIV infections, with the highest risk among Black Africans living in poor communities. Most HIV prevention interventions target women or men separately and only a small number target couples jointly. This study examines varying strategies to engage women and men around HIV prevention and improved couple interactions. The study comprises three arms: (1) a couple-based intervention delivered to women and men jointly; (2) women and men both offered a gender-focused intervention that is delivered to them separately; and (3) an intervention offered to women only and their male partners receive standard HIV testing and counseling (comparison arm). Between June 2010 and April 2012, men were identified in and around drinking establishments in a large disadvantaged community in Cape Town and asked to participate in the study if they drink regularly, had recent unprotected sex with their partner, and have a female partner who was willing to participate in the study. A total of 299 couples completed the baseline assessment and 276 were included in the analysis of sexual risk, partner communication, conflict resolution, and gender norm outcomes at baseline and six-month follow-up. Couples that participated in the couple-level intervention and couples where both partners received the intervention separately had better couple-level gender norms than couples in the comparison arm (women only receive intervention). Further, couples in the couple-level intervention and the both partners exposed separately arms were more likely to have the man only report consistent condom use than neither partner report consistent condom use than couples in the comparison arm. Community-based HIV prevention intervention programs need to consider strategies to engage women and men and, if feasible, reach both partners jointly. Couple-level interventions are promising to improve gender norms and subsequently improve health outcomes, including reduced HIV risk among women, men, and couples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Probing and Exploiting the Interplay between Nuclear and Electronic Motion in Charge Transfer Processes.

PubMed

Delor, Milan; Sazanovich, Igor V; Towrie, Michael; Weinstein, Julia A

2015-04-21

The Born-Oppenheimer approximation refers to the assumption that the nuclear and electronic wave functions describing a molecular system evolve and can be determined independently. It is now well-known that this approximation often breaks down and that nuclear-electronic (vibronic) coupling contributes greatly to the ultrafast photophysics and photochemistry observed in many systems ranging from simple molecules to biological organisms. In order to probe vibronic coupling in a time-dependent manner, one must use spectroscopic tools capable of correlating the motions of electrons and nuclei on an ultrafast time scale. Recent developments in nonlinear multidimensional electronic and vibrational spectroscopies allow monitoring both electronic and structural factors with unprecedented time and spatial resolution. In this Account, we present recent studies from our group that make use of different variants of frequency-domain transient two-dimensional infrared (T-2DIR) spectroscopy, a pulse sequence combining electronic and vibrational excitations in the form of a UV-visible pump, a narrowband (12 cm(-1)) IR pump, and a broadband (400 cm(-1)) IR probe. In the first example, T-2DIR is used to directly compare vibrational dynamics in the ground and relaxed electronic excited states of Re(Cl)(CO)3(4,4'-diethylester-2,2'-bipyridine) and Ru(4,4'-diethylester-2,2'-bipyridine)2(NCS)2, prototypical charge transfer complexes used in photocatalytic CO2 reduction and electron injection in dye-sensitized solar cells. The experiments show that intramolecular vibrational redistribution (IVR) and vibrational energy transfer (VET) are up to an order of magnitude faster in the triplet charge transfer excited state than in the ground state. These results show the influence of electronic arrangement on vibrational coupling patterns, with direct implications for vibronic coupling mechanisms in charge transfer excited states. In the second example, we show unambiguously that electronic and vibrational movement are coupled in a donor-bridge-acceptor complex based on a Pt(II) trans-acetylide design motif. Time-resolved IR (TRIR) spectroscopy reveals that the rate of electron transfer (ET) is highly dependent on the amount of excess energy localized on the bridge following electronic excitation. Using an adaptation of T-2DIR, we are able to selectively perturb bridge-localized vibrational modes during charge separation, resulting in the donor-acceptor charge separation pathway being completely switched off, with all excess energy redirected toward the formation of a long-lived intraligand triplet state. A series of control experiments reveal that this effect is mode specific: it is only when the high-frequency bridging C≡C stretching mode is pumped that radical changes in photoproduct yields are observed. These experiments therefore suggest that one may perturb electronic movement by stimulating structural motion along the reaction coordinate using IR light. These studies add to a growing body of evidence suggesting that controlling the pathways and efficiency of charge transfer may be achieved through synthetic and perturbative approaches aiming to modulate vibronic coupling. Achieving such control would represent a breakthrough for charge transfer-based applications such as solar energy conversion and molecular electronics.

Observation and explanation of two-dimensional interconversion of oximes with multiple heart-cutting using comprehensive multidimensional gas chromatography.

PubMed

Kulsing, Chadin; Nolvachai, Yada; Wong, Yong Foo; Glouzman, Melissa I; Marriott, Philip J

2018-04-20

Real-time interconversion processes produce unconventional peak broadening in gas chromatography (GC), and can be used to generate kinetic and thermodynamic data. In this study, an unusual separation situation in comprehensive two dimensional GC where two dimensional interconversion (i.e. a raised plateau in both first and second dimension, 1 D and 2 D) was observed in analysis of oxime isomers. This resulted in a characteristic and unusual rectangular peak shape in the two dimensional result. A related theoretical approach was introduced to explain the peak shape supported by simulation results which can be varied depending on concentration profiles and kinetics of the process. The simulated results were supported by experimental results obtained by a comprehensive heart-cut multidimensional GC (H/C MDGC) approach which was developed to clearly investigate isomerisation of E/Z oxime molecules in both 1 D and 2 D separations under different isothermal conditions. The carrier gas flow and oven temperature were selected according to initial results for 1D interconversion on a poly(ethyleneglycol) stationary phase, which was further used in both 1 D and 2 D separations to result in broad zones of oxime interconversion in both dimensions. The method involved repetitive injections of oxime sample, then sampling contiguous fractions of sample into a long 2 D column which is intended to promote considerable interconversion. Comprehensiveness arises from the fact that the whole sample is sampled from the 1 D to the 2 D column, with the long 2 D column replacing the short 2 D column used in classical comprehensive two-dimensional gas chromatography, where the latter will not promote sufficient interconversion. Data processing and presentation permits a 'rectangular' distribution corresponding to the separated compounds, characteristic of this experiment. Copyright © 2018 Elsevier B.V. All rights reserved.

Expanding the Therapy Paradigm with Queer Couples: A Relational Intersectional Lens.

PubMed

Addison, Sheila M; Coolhart, Deborah

2015-09-01

North American and global cultures in general-and the field of Couple and Family Therapy in particular-have made significant strides toward recognizing and validating LGBTQ identities and relationships. However, clinical assessment and conceptualization of queer couples still lack the complexity needed to encompass the issues involved in treatment. Existing literature provides clinicians a basic understanding of queer couples and the dynamics that make them unique from nonqueer couples. However, much of this knowledge has been normed on White middle-class couples and has rarely included couples with transgender or bisexual members. This article invites clinicians and researchers to apply a feminist model of intersectionality to understand queer couples. Our proposed intersectional lens considers multiple axes of identity and power and their interrelationships (Crenshaw, 1989, 1991). We argue that intersectionality is important for understanding all identities, whether privileged or marginalized (Falicov, 2003). This application of the concept of intersectionality is unique in its relational focus, emphasizing how partners' complex individual identities overlap with and intersect with one another. Additionally, this lens considers how the therapists' and clients' multidimensional identities intersect. Three case studies are presented to illustrate application of the intersectional lens. In each case, exploring the partners' multiple social locations, their influences on one another, and the therapist's intersections of identity all proved critical to the direction of therapy. © 2015 Family Process Institute.

Integrated multidimensional and comprehensive 2D GC analysis of fatty acid methyl esters.

PubMed

Zeng, Annie Xu; Chin, Sung-Tong; Marriott, Philip J

2013-03-01

Fatty acid methyl ester (FAME) profiling in complex fish oil and milk fat samples was studied using integrated comprehensive 2D GC (GC × GC) and multidimensional GC (MDGC). Using GC × GC, FAME compounds--cis- and trans-isomers, and essential fatty acid isomers--ranging from C18 to C22 in fish oil and C18 in milk fat were clearly displayed in contour plot format according to structural properties and patterns, further identified based on authentic standards. Incompletely resolved regions were subjected to MDGC, with Cn (n = 18, 20) zones transferred to a (2)D column. Elution behavior of C18 FAME on various (2)D column phases (ionic liquids IL111, IL100, IL76, and modified PEG) was evaluated. Individual isolated Cn zones demonstrated about four-fold increased peak capacities. The IL100 provided superior separation, good peak shape, and utilization of elution space. For milk fat-derived FAME, the (2)D chromatogram revealed at least three peaks corresponding to C18:1, more than six peaks for cis/trans-C18:2 isomers, and two peaks for C18:3. More than 17 peaks were obtained for the C20 region of fish oil-derived FAMEs using MDGC, compared with ten peaks using GC × GC. The MDGC strategy is useful for improved FAME isomer separation and confirmation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneously driven linear and nonlinear spatial encoding fields in MRI.

PubMed

Gallichan, Daniel; Cocosco, Chris A; Dewdney, Andrew; Schultz, Gerrit; Welz, Anna; Hennig, Jürgen; Zaitsev, Maxim

2011-03-01

Spatial encoding in MRI is conventionally achieved by the application of switchable linear encoding fields. The general concept of the recently introduced PatLoc (Parallel Imaging Technique using Localized Gradients) encoding is to use nonlinear fields to achieve spatial encoding. Relaxing the requirement that the encoding fields must be linear may lead to improved gradient performance or reduced peripheral nerve stimulation. In this work, a custom-built insert coil capable of generating two independent quadratic encoding fields was driven with high-performance amplifiers within a clinical MR system. In combination with the three linear encoding fields, the combined hardware is capable of independently manipulating five spatial encoding fields. With the linear z-gradient used for slice-selection, there remain four separate channels to encode a 2D-image. To compare trajectories of such multidimensional encoding, the concept of a local k-space is developed. Through simulations, reconstructions using six gradient-encoding strategies were compared, including Cartesian encoding separately or simultaneously on both PatLoc and linear gradients as well as two versions of a radial-based in/out trajectory. Corresponding experiments confirmed that such multidimensional encoding is practically achievable and demonstrated that the new radial-based trajectory offers the PatLoc property of variable spatial resolution while maintaining finite resolution across the entire field-of-view. Copyright © 2010 Wiley-Liss, Inc.

Solid state transport-based thermoelectric converter

DOEpatents

Hu, Zhiyu

2010-04-13

A solid state thermoelectric converter includes a thermally insulating separator layer, a semiconducting collector and an electron emitter. The electron emitter comprises a metal nanoparticle layer or plurality of metal nanocatalyst particles disposed on one side of said separator layer. A first electrically conductive lead is electrically coupled to the electron emitter. The collector layer is disposed on the other side of the separator layer, wherein the thickness of the separator layer is less than 1 .mu.m. A second conductive lead is electrically coupled to the collector layer.

The Economic Foundations of Cohabiting Couples' Union Transitions.

PubMed

Ishizuka, Patrick

2018-04-01

In recent decades, cohabitation has become an increasingly important relationship context for U.S. adults and their children, a union status characterized by high levels of instability. To understand why some cohabiting couples marry but others separate, researchers have drawn on theories emphasizing the benefits of specialization, the persistence of the male breadwinner norm, low income as a source of stress and conflict, and rising economic standards associated with marriage (the marriage bar). Because of conflicting evidence and data constraints, however, important theoretical questions remain. This study uses survival analysis with prospective monthly data from nationally representative panels of the Survey of Income and Program Participation from 1996-2013 to test alternative theories of how money and work affect whether cohabiting couples marry or separate. Analyses indicate that the economic foundations of cohabiting couples' union transitions do not lie in economic specialization or only men's ability to be good providers. Instead, results for marriage support marriage bar theory: adjusting for couples' absolute earnings, increases in wealth and couples' earnings relative to a standard associated with marriage strongly predict marriage. For dissolution, couples with higher and more equal earnings are significantly less likely to separate. Findings demonstrate that within-couple earnings equality promotes stability, and between-couple inequalities in economic resources are critical in producing inequalities in couples' relationship outcomes.

HPLC-Chip/MS Technology in Proteomic Profiling

NASA Astrophysics Data System (ADS)

Vollmer, Martin; van de Goor, Tom

HPLC-chip/MS is a novel nanoflow analytical technology conducted on a microfabricated chip that allows for highly efficient HPLC separation and superior sensitive MS detection of complex proteomic mixtures. This is possible through on-chip preconcentration and separation with fluidic connection made automatically in a leak-tight fashion. Minimum precolumn and postcolumn peak dispersion and uncompromised ease of use result in compounds eluting in bands of only a few nanoliters. The chip is fabricated out of bio-inert polyimide-containing channels and integrated chip structures, such as an electrospray emitter, columns, and frits manufactured by laser ablation technology. Meanwhile, a variety of HPLC-chips differing in design and stationary phase are commercially available, which provide a comprehensive solution for applications in proteomics, glycomics, biomarker, and pharmaceutical discovery. The HPLC-chip can also be easily integrated into a multidimensional separation workflow where different orthogonal separation techniques are combined to solve a highly complex separation problems. In this chapter, we describe in detail the methodological chip usage and functionality and its application in the elucidation of the protein profile of human nucleoli.

Screening efficiency of the self-report version of the Multidimensional Anxiety Scale for Children in a highly comorbid inpatient sample.

PubMed

Skarphedinsson, Gudmundur; Villabø, Marianne A; Lauth, Bertrand

2015-01-01

The Multidimensional Anxiety Scale for Children (MASC) is a widely used self-report questionnaire for the assessment of anxiety symptoms in children and adolescents with well documented predictive validity of the total score and subscales in internalizing and mixed clinical samples. However, no data exist on the screening efficiency in an inpatient sample of adolescents. To examine the psychometric properties and screening efficiency of the MASC in a high comorbid inpatient sample. The current study used receiver operating characteristic (ROC) analyses to investigate the predictive value of the MASC total and subscale scores for the Schedule for Affective Disorders and Schizophrenia for School-age children-Present and Lifetime version (K-SADS-PL), DSM-IV diagnoses of generalized anxiety disorder (GAD), separation anxiety disorder (SAD) and social phobia (SoP) in a highly comorbid inpatient sample of adolescents (11-18 years). The MASC total score predicted any anxiety disorder (AD) and GAD moderately well. Physical symptoms predicted GAD moderately well. Social anxiety and separation anxiety/panic did not predict SoP or SAD, respectively. Physical symptoms and harm avoidance also predicted the presence of major depressive disorder. The findings support the utility of the MASC total score to predict the presence of any AD and GAD. However, the utility of the social anxiety and separation anxiety/panic subscales showed limited utility to predict the presence of SAD and SoP, respectively. The MASC has probably a more limited function in screening for AD among a highly comorbid inpatient sample of severely affected adolescents. Our results should be interpreted in the light of a small, mixed sample of inpatient adolescents.

Robust Angle Estimation for MIMO Radar with the Coexistence of Mutual Coupling and Colored Noise.

PubMed

Wang, Junxiang; Wang, Xianpeng; Xu, Dingjie; Bi, Guoan

2018-03-09

This paper deals with joint estimation of direction-of-departure (DOD) and direction-of- arrival (DOA) in bistatic multiple-input multiple-output (MIMO) radar with the coexistence of unknown mutual coupling and spatial colored noise by developing a novel robust covariance tensor-based angle estimation method. In the proposed method, a third-order tensor is firstly formulated for capturing the multidimensional nature of the received data. Then taking advantage of the temporal uncorrelated characteristic of colored noise and the banded complex symmetric Toeplitz structure of the mutual coupling matrices, a novel fourth-order covariance tensor is constructed for eliminating the influence of both spatial colored noise and mutual coupling. After a robust signal subspace estimation is obtained by using the higher-order singular value decomposition (HOSVD) technique, the rotational invariance technique is applied to achieve the DODs and DOAs. Compared with the existing HOSVD-based subspace methods, the proposed method can provide superior angle estimation performance and automatically jointly perform the DODs and DOAs. Results from numerical experiments are presented to verify the effectiveness of the proposed method.

Neuronal synchrony: Peculiarity and generality

PubMed Central

Nowotny, Thomas; Huerta, Ramon; Rabinovich, Mikhail I.

2008-01-01

Synchronization in neuronal systems is a new and intriguing application of dynamical systems theory. Why are neuronal systems different as a subject for synchronization? (1) Neurons in themselves are multidimensional nonlinear systems that are able to exhibit a wide variety of different activity patterns. Their “dynamical repertoire” includes regular or chaotic spiking, regular or chaotic bursting, multistability, and complex transient regimes. (2) Usually, neuronal oscillations are the result of the cooperative activity of many synaptically connected neurons (a neuronal circuit). Thus, it is necessary to consider synchronization between different neuronal circuits as well. (3) The synapses that implement the coupling between neurons are also dynamical elements and their intrinsic dynamics influences the process of synchronization or entrainment significantly. In this review we will focus on four new problems: (i) the synchronization in minimal neuronal networks with plastic synapses (synchronization with activity dependent coupling), (ii) synchronization of bursts that are generated by a group of nonsymmetrically coupled inhibitory neurons (heteroclinic synchronization), (iii) the coordination of activities of two coupled neuronal networks (partial synchronization of small composite structures), and (iv) coarse grained synchronization in larger systems (synchronization on a mesoscopic scale). PMID:19045493

Robust Angle Estimation for MIMO Radar with the Coexistence of Mutual Coupling and Colored Noise

PubMed Central

Wang, Junxiang; Wang, Xianpeng; Xu, Dingjie; Bi, Guoan

2018-01-01

This paper deals with joint estimation of direction-of-departure (DOD) and direction-of- arrival (DOA) in bistatic multiple-input multiple-output (MIMO) radar with the coexistence of unknown mutual coupling and spatial colored noise by developing a novel robust covariance tensor-based angle estimation method. In the proposed method, a third-order tensor is firstly formulated for capturing the multidimensional nature of the received data. Then taking advantage of the temporal uncorrelated characteristic of colored noise and the banded complex symmetric Toeplitz structure of the mutual coupling matrices, a novel fourth-order covariance tensor is constructed for eliminating the influence of both spatial colored noise and mutual coupling. After a robust signal subspace estimation is obtained by using the higher-order singular value decomposition (HOSVD) technique, the rotational invariance technique is applied to achieve the DODs and DOAs. Compared with the existing HOSVD-based subspace methods, the proposed method can provide superior angle estimation performance and automatically jointly perform the DODs and DOAs. Results from numerical experiments are presented to verify the effectiveness of the proposed method. PMID:29522499

Selective aqueous extraction of organics coupled with trapping by membrane separation

DOEpatents

van Eikeren, Paul; Brose, Daniel J.; Ray, Roderick J.

1991-01-01

An improvement to processes for the selective extractation of organic solutes from organic solvents by water-based extractants is disclosed, the improvement comprising coupling various membrane separation processes with the organic extraction process, the membrane separation process being utilized to continuously recycle the water-based extractant and at the same time selectively remove or concentrate organic solute from the water-based extractant.

Separation of the atmospheric variability into non-Gaussian multidimensional sources by projection pursuit techniques

NASA Astrophysics Data System (ADS)

Pires, Carlos A. L.; Ribeiro, Andreia F. S.

2017-02-01

We develop an expansion of space-distributed time series into statistically independent uncorrelated subspaces (statistical sources) of low-dimension and exhibiting enhanced non-Gaussian probability distributions with geometrically simple chosen shapes (projection pursuit rationale). The method relies upon a generalization of the principal component analysis that is optimal for Gaussian mixed signals and of the independent component analysis (ICA), optimized to split non-Gaussian scalar sources. The proposed method, supported by information theory concepts and methods, is the independent subspace analysis (ISA) that looks for multi-dimensional, intrinsically synergetic subspaces such as dyads (2D) and triads (3D), not separable by ICA. Basically, we optimize rotated variables maximizing certain nonlinear correlations (contrast functions) coming from the non-Gaussianity of the joint distribution. As a by-product, it provides nonlinear variable changes `unfolding' the subspaces into nearly Gaussian scalars of easier post-processing. Moreover, the new variables still work as nonlinear data exploratory indices of the non-Gaussian variability of the analysed climatic and geophysical fields. The method (ISA, followed by nonlinear unfolding) is tested into three datasets. The first one comes from the Lorenz'63 three-dimensional chaotic model, showing a clear separation into a non-Gaussian dyad plus an independent scalar. The second one is a mixture of propagating waves of random correlated phases in which the emergence of triadic wave resonances imprints a statistical signature in terms of a non-Gaussian non-separable triad. Finally the method is applied to the monthly variability of a high-dimensional quasi-geostrophic (QG) atmospheric model, applied to the Northern Hemispheric winter. We find that quite enhanced non-Gaussian dyads of parabolic shape, perform much better than the unrotated variables in which concerns the separation of the four model's centroid regimes (positive and negative phases of the Arctic Oscillation and of the North Atlantic Oscillation). Triads are also likely in the QG model but of weaker expression than dyads due to the imposed shape and dimension. The study emphasizes the existence of nonlinear dyadic and triadic nonlinear teleconnections.

Associations among Aspects of Interpersonal Power and Relationship Functioning in Adolescent Romantic Couples

PubMed Central

Bentley, Charles G; Galliher, Renee V; Ferguson, Tamara J

2008-01-01

This study used a multidimensional assessment of interpersonal power to examine associations between indices of relationship power and relationship functioning in 92 adolescent romantic couples recruited from rural communities in the Rocky Mountain region of the United States. Significant differences emerged between girlfriends and boyfriends in their reports of decision making authority, perceptions of humiliating behaviors by the partner, and ratings of themselves giving-in to their partners in a videotaped interaction task. In addition, indices of interpersonal power were associated with dating aggression and relationship satisfaction for both girlfriends and boyfriends, although gender differences emerged in the patterns of association between power and outcomes. Results are discussed in light of current developmental, feminist, and social psychological theories of interpersonal power in romantic relationships. PMID:18776943

Laser dynamics in transversely inhomogeneous plasma and its relevance to wakefield acceleration

NASA Astrophysics Data System (ADS)

Pathak, V. B.; Vieira, J.; Silva, L. O.; Nam, Chang Hee

2018-05-01

We present full set of coupled equations describing the weakly relativistic dynamics of a laser in a plasma with transverse inhomogeneity. We apply variational principle approach to obtain these coupled equations governing laser spot-size, transverse wavenumber, curvature, transverse centroid, etc. We observe that such plasma inhomogeneity can lead to stronger self-focusing. We further discuss the guiding conditions of laser in parabolic plasma channels. With the help of multi-dimensional particle in cell simulations the study is extended to the blowout regime of laser wakefield acceleration to show laser as well as self-injected electron bunch steering in plasma to generate unconventional particle trajectories. Our simulation results demonstrate that such transverse inhomogeneities due to asymmetric self focusing lead to asymmetric bubble excitation, thus inducing off-axis self-injection.

Characterization of crude oil biomarkers using comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry.

PubMed

Mogollón, Noroska Gabriela Salazar; Prata, Paloma Santana; Dos Reis, Jadson Zeni; Neto, Eugênio Vaz Dos Santos; Augusto, Fabio

2016-09-01

Oil samples from Recôncavo basin (NE Brazil), previously analyzed by traditional techniques such as gas chromatography coupled to tandem mass spectrometry, were evaluated using comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry and comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry along with simplified methods of samples preparation to evaluate the differences and advantages of these analytical techniques to better understand the development of the organic matter in this basin without altering the normal distribution of the compounds in the samples. As a result, the geochemical parameters calculated by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry described better the origin, maturity, and biodegradation of both samples probably by increased selectivity, resolution, and sensitivity inherent of the multidimensional technique. Additionally, the detection of the compounds such as, the C(14α-) homo-26-nor-17α-hopane series, diamoretanes, nor-spergulanes, C19 -C26 A-nor-steranes and 4α-methylsteranes resolved and detected by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry were key to classify and differentiate these lacustrine samples according to their maturity and deposition conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Numerical Tools for the Investigation of Plasma Detachment from Magnetic Nozzles

NASA Technical Reports Server (NTRS)

Sankaran, Kamesh; Polzin, Kurt A.

2007-01-01

A multidimensional numerical simulation framework aimed at investigating the process of plasma detachment from a magnetic nozzle is introduced. An existing numerical code based on a magnetohydrodynamic formulation of the plasma flow equations that accounts for various dispersive and dissipative processes in plasmas was significantly enhanced to allow for the modeling of axisymmetric domains containing three.dimensiunai momentum and magnetic flux vectors. A separate magnetostatic solver was used to simulate the applied magnetic field topologies found in various nozzle experiments. Numerical results from a magnetic diffusion test problem in which all three components of the magnetic field were present exhibit excellent quantitative agreement with the analytical solution, and the lack of numerical instabilities due to fluctuations in the value of del(raised dot)B indicate that the conservative MHD framework with dissipative effects is well-suited for multi-dimensional analysis of magnetic nozzles. Further studies will focus on modeling literature experiments both for the purpose of code validation and to extract physical insight regarding the mechanisms driving detachment.

Determination of mono- and non-o,o′-chlorine substituted polychlorinated biphenyls in Aroclors and environmental samples

USGS Publications Warehouse

Schwartz, Ted R.; Tillitt, Donald E.; Feltz, Kevin P.; Peterman, Paul H.

1993-01-01

High resolution capillary gas chromatography (GC) is the best known technique for the separation of complex mixtures; however, no single GC column has yet separated all 209 congeners of polychlorinated biphenyls (PCBs). A number of coeluting PCB congener pairs exist, and even under favorable separation conditions such as with multidimensional GC, assignment of peak identities to known PCB structures is tedious, subject to errors from other contaminants, and requires enrichment to achieve the necessary detection limits for the most toxic PCB congeners. Routine analysis of PCBs is also complicated by coelution with other halogenated hydrocarbons such as naphthalenes, terphenyls, dibenzofurans, and pesticides. Therefore, techniques for class separations of PCBs prior to gas chromatography must be developed. These techniques should separate PCB congeners along lines that have environmental or toxicological significance. The unique ability of activated carbon to separate halogenated aromatics on the basis of molecular planarity and degree of halogenation has been demonstrated. We present a method that uses dispersed carbon on glass fibers and commercially available instrumentation to fractionate and determine mono- and non-o,o′-chlorine substituted PCB congeners in Aroclors and environmental samples.

Necessary Contributions of Human Frontal Lobe Subregions to Reward Learning in a Dynamic, Multidimensional Environment.

PubMed

Vaidya, Avinash R; Fellows, Lesley K

2016-09-21

Real-world decisions are typically made between options that vary along multiple dimensions, requiring prioritization of the important dimensions to support optimal choice. Learning in this setting depends on attributing decision outcomes to the dimensions with predictive relevance rather than to dimensions that are irrelevant and nonpredictive. This attribution problem is computationally challenging, and likely requires an interplay between selective attention and reward learning. Both these processes have been separately linked to the prefrontal cortex, but little is known about how they combine to support learning the reward value of multidimensional stimuli. Here, we examined the necessary contributions of frontal lobe subregions in attributing feedback to relevant and irrelevant dimensions on a trial-by-trial basis in humans. Patients with focal frontal lobe damage completed a demanding reward learning task where options varied on three dimensions, only one of which predicted reward. Participants with left lateral frontal lobe damage attributed rewards to irrelevant dimensions, rather than the relevant dimension. Damage to the ventromedial frontal lobe also impaired learning about the relevant dimension, but did not increase reward attribution to irrelevant dimensions. The results argue for distinct roles for these two regions in learning the value of multidimensional decision options under dynamic conditions, with the lateral frontal lobe required for selecting the relevant dimension to associate with reward, and the ventromedial frontal lobe required to learn the reward association itself. The real world is complex and multidimensional; how do we attribute rewards to predictive features when surrounded by competing cues? Here, we tested the critical involvement of human frontal lobe subregions in a probabilistic, multidimensional learning environment, asking whether focal lesions affected trial-by-trial attribution of feedback to relevant and irrelevant dimensions. The left lateral frontal lobe was required for filtering option dimensions to allow appropriate feedback attribution, while the ventromedial frontal lobe was necessary for learning the value of features in the relevant dimension. These findings argue that selective attention and associative learning processes mediated by anatomically distinct frontal lobe subregions are both critical for adaptive choice in more complex, ecologically valid settings. Copyright © 2016 the authors 0270-6474/16/369843-16$15.00/0.

Quantifying Stream-Aquifer Exchanges Over Scales: the Concept of Nested Interfaces

NASA Astrophysics Data System (ADS)

Flipo, N.; Mouhri, A.; Labarthe, B.; Saleh, F. S.

2013-12-01

Recent developments in hydrological modelling are based on a view of the interface being a single continuum through which water flows. These coupled hydrological-hydrogeological models, emphasizing the importance of the stream-aquifer interface (SAI), are more and more used in hydrological sciences for pluri-disciplinary studies aiming at questioning environmental issues. This notion of a single continuum comes from the historical modelling of hydrosystems based on the hypothesis of a homogeneous media that led to the Darcy law. Nowadays, there is a need to first bridge the gap between hydrological and eco-hydrological views of the SAIs, and, second, to rationalize the modelling of SAI within a consistent framework that fully takes into account the multi-dimensionality of the SAIs. We first define the concept of nested SAIs as a key transitional component of continental hydrosystem. We then demonstrate the usefulness of the concept for the multi-dimensional study of the SAI, with a special emphasis on the stream network which is identified as the key component for scaling hydrological processes occurring at the interface. Finally we focus on SAI modelling at various scales with up-to-date methodologies and give some guidance for the multi-dimensional modelling of the interface using the innovative methodology MIM (Measurements-Interpolation-Modelling), which is graphically developed. MIM scales in space three pools of methods needed to fully understand SAIs. The outcome of MIM is the localization in space of the type of SAI that can be studied by a given approach. The efficiency of the method is illustrated from the local (approx. 1m) to the regional scale (> 10 000 km2) with two examples from the Paris basin (France). The first one consists in the implementation of a sampling system of stream-aquifer exchanges, which is coupled with local 2D thermo-hydro models and a pseudo 3D hydro(geo)logical model at the watershed scale (40 km2). The quantification of monthly stream-aquifer exchanges over 14 000 km of river network in the Paris basin (74 000 km2) corresponds to a unique regional scale example.

Optimal control of orientation and entanglement for two dipole-dipole coupled quantum planar rotors.

PubMed

Yu, Hongling; Ho, Tak-San; Rabitz, Herschel

2018-05-09

Optimal control simulations are performed for orientation and entanglement of two dipole-dipole coupled identical quantum rotors. The rotors at various fixed separations lie on a model non-interacting plane with an applied control field. It is shown that optimal control of orientation or entanglement represents two contrasting control scenarios. In particular, the maximally oriented state (MOS) of the two rotors has a zero entanglement entropy and is readily attainable at all rotor separations. Whereas, the contrasting maximally entangled state (MES) has a zero orientation expectation value and is most conveniently attainable at small separations where the dipole-dipole coupling is strong. It is demonstrated that the peak orientation expectation value attained by the MOS at large separations exhibits a long time revival pattern due to the small energy splittings arising form the extremely weak dipole-dipole coupling between the degenerate product states of the two free rotors. Moreover, it is found that the peak entanglement entropy value attained by the MES remains largely unchanged as the two rotors are transported to large separations after turning off the control field. Finally, optimal control simulations of transition dynamics between the MOS and the MES reveal the intricate interplay between orientation and entanglement.

On the Einstein-Podolsky-Rosen Paradox

NASA Astrophysics Data System (ADS)

McWeeny, Roy

Central to the EPR paradox is a [`]thought experiment' in which two spins are initially coupled to a state with S = 0 and are then separated to a large distance, at which they can be separately observed. Quantum mechanics apparently predicts that the two spins remain forever coupled, but this conflicts with Einstein's principle of [`]locality' or [`]separability', according to which spatially well separated systems must be independent, no matter how strongly they have interacted in the past. It is now widely held that Einstein was wrong and that [`]non-locality' follows inevitably from quantum mechanics i.e. that even distant systems are never truly separable.

Sheathless interface for coupling capillary electrophoresis with mass spectrometry

DOEpatents

Wang, Chenchen; Tang, Keqi; Smith, Richard D.

2014-06-17

A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

Safety Modification of Cam-and-Groove Hose Coupling

NASA Technical Reports Server (NTRS)

Schwindt, Paul; Littlefield, Alan

2008-01-01

A modification has been made in the mating halves of a cam-and-groove hose coupling to prevent rapid separation of the halves in the event that the cam levers are released while the fluid in the hose is pressurized. The need for this modification arises because commercial off-the-shelf cam-and-groove hose-coupling halves do not incorporate safety features to prevent separation in the pressurized state. Especially when the pressurized fluid is compressible (e.g., steam or compressed air), the separated halves can be propelled with considerable energy, causing personal injury and/or property damage. Therefore, one purpose served by the modification is to provide for venting to release compressive energy in a contained and safe manner while preventing personal injury and/or property damage. Another purpose served by the modification, during the process of connecting the coupling halves, is to ensure that the coupling halves are properly aligned before the cam levers can be locked into position.

Coupled thermal-fluid-mechanics analysis of twin roll casting of A7075 aluminum alloy

NASA Astrophysics Data System (ADS)

Lee, Yun-Soo; Kim, Hyoung-Wook; Cho, Jae-Hyung; Chun, Se-Hwan

2017-09-01

Better understanding of temperature distribution and roll separation force during twin roll casting of aluminum alloys is critical to successfully fabricate good quality of aluminum strips. Therefore, the simulation techniques are widely applied to understand the twin roll casting process in a comprehensive way and to reduce the experimental time and cost of trial and error. However, most of the conventional approaches are considered thermally coupled flow, or thermally coupled mechanical behaviors. In this study, a fully coupled thermal-fluid-mechanical analysis of twin roll casting of A7075 aluminum strips was carried out using the finite element method. Temperature profile, liquid fraction and metal flow of aluminum strips with different thickness were predicted. Roll separation force and roll temperatures were experimentally obtained from a pilot-scale twin roll caster, and those results were compared with model predictions. Coupling the fluid of the liquid melt to the thermal and mechanical modeling reasonably predicted roll temperature distribution and roll separation force during twin roll casting.

Probing Subdiffraction Limit Separations with Plasmon Coupling Microscopy: Concepts and Applications

PubMed Central

Wu, Linxi

2014-01-01

Due to their advantageous materials properties, noble metal nanoparticles are versatile tools in biosensing and imaging. A characteristic feature of gold and silver nanoparticles is their ability to sustain localized surface plasmons that provide both large optical cross-sections and extraordinary photophysical stability. Plasmon Coupling Microscopy takes advantage of the beneficial optical properties and utilizes electromagnetic near-field coupling between individual noble metal nanoparticle labels to resolve subdiffraction limit separations in an all-optical fashion. This Tutorial provides an introduction into the physical concepts underlying distance dependent plasmon coupling, discusses potential experimental implementations of Plasmon Coupling Microscopy, and reviews applications in the area of biosensing and imaging. PMID:24390574

Simulating Chiral Magnetic and Separation Effects with Spin-Orbit Coupled Atomic Gases

PubMed Central

Huang, Xu-Guang

2016-01-01

The chiral magnetic and chiral separation effects—quantum-anomaly-induced electric current and chiral current along an external magnetic field in parity-odd quark-gluon plasma—have received intense studies in the community of heavy-ion collision physics. We show that analogous effects occur in rotating trapped Fermi gases with Weyl-Zeeman spin-orbit coupling where the rotation plays the role of an external magnetic field. These effects can induce a mass quadrupole in the atomic cloud along the rotation axis which may be tested in future experiments. Our results suggest that the spin-orbit coupled atomic gases are potential simulators of the chiral magnetic and separation effects. PMID:26868084

Quantification of polychlorinated dibenzo-p-dioxins and dibenzofurans by direct injection of sample extract into the comprehensive multidimensional gas chromatograph/high-resolution time-of-flight mass spectrometer.

PubMed

Shunji, Hashimoto; Yoshikatsu, Takazawa; Akihiro, Fushimi; Hiroyasu, Ito; Kiyoshi, Tanabe; Yasuyuki, Shibata; Masa-aki, Ubukata; Akihiko, Kusai; Kazuo, Tanaka; Hideyuki, Otsuka; Katsunori, Anezaki

2008-01-18

Polychlorinated dibenzo-p-dioxins and dibenzofurans in crude extracts of fly ash and flue gas from municipal waste incinerators were quantified using a comprehensive multidimensional gas chromatograph (GC x GC) coupled to a high-resolution time-of-flight mass spectrometer (HR-TOFMS). For identification and quantification, we developed our own program to prepare 3D chromatograms of selected mass numbers from the data of the GC x GC/HR-TOFMS. Isolation of all congeners with a TCDD toxic equivalency factor from the other isomers by only one injection was confirmed. The instrumental detection limit of TCDD on the GC x GC/HR-TOFMS was 0.9 pg by the relative calibration method. Quantification of these substances in the crude extracts was achieved by direct injection to the GC x GC/HR-TOFMS. The results agree with the values obtained using a generic gas chromatography/high-resolution mass spectrometry (GC/HRMS) system. It was confirmed that measurement by high-resolution TOFMS and GC x GC effectively reduces interference from other chemicals.

Comprehensive authentication of (E)-alpha(beta)-ionone from raspberries, using constant flow MDGC-C/P-IRMS and enantio-MDGC-MS.

PubMed

Sewenig, Sabine; Bullinger, Dino; Hener, Uwe; Mosandl, Armin

2005-02-23

A new coupling system of GC-GC, connected via a Multi Column Switching Device MCS2 for measuring isotope ratios, is introduced. By means of several standard substances the precise and accurate measurement of isotopic values is proved. First applications concerning the authentication of raspberry aroma compounds are established. Consequently, the combination of constant flow multidimensional gas chromatography-combustion/pyrolysis-isotope ratio mass spectrometry (MDGC-C/P-IRMS) is applied to the authenticity assessment of (E)-alpha(beta)-ionone from six different raspberry cultivars. Furthermore, 12 commercially available raspberry products and samples of (E)-alpha(beta)-ionone, some declared to be natural, are investigated. delta(2)Eta(V)(-)(SMOW) and delta(13)C(V)(-)(PDB) values of (E)-alpha(beta)-ionone are determined, and characteristic authenticity ranges were concluded from raspberries by correlation of both delta(2)Eta(V)(-)(SMOW) and delta(13)C( V)(-)(PDB) values. The results are correlated with the determination of enantiomeric purities of (E)-alpha-ionone, using stir bar sorptive extraction enantio-multidimensional gas chromatography mass spectrometry (SBSE-enantio-MDGC-MS).

Non-metric multidimensional scaling and human risks of heavy metal concentrations in wild marine organisms from the Maowei Sea, the Beibu Gulf, South China Sea.

PubMed

Gu, Yang-Guang; Huang, Hong-Hui; Liu, Yong; Gong, Xiu-Yu; Liao, Xiu-Li

2018-04-01

We investigated heavy metal concentrations in wild marine organisms from Maowei Sea, a significant gulf of low-latitude developing regions of the Beibu Gulf, South China Sea. Twenty species, comprising fish, cephalopods, and crustaceans were collected and analyzed for heavy metals. Heavy metal levels (mg/kg, wet weight) in the aquatic organism samples were: 0.003-1.800 for Cd, 0.02-0.14 for Pb, 0.10-0.63 for Cr, 0.20-77.50 for Cu, 9.50-64.60 for Zn, 0.006-0.066 for Hg, and 0.10-1.50 for As. Non-metric multidimensional scaling coupled with cluster analysis revealed two groupings that mainly resulted from different species of the metals in marine organisms. The highest concentrations of Cd, Pb, Cr, Ni, Cu, Zn, Hg, and As were found in species of cephalopods. Health risk assessment based on the target hazard quotients (THQ) and total THQ indicated no significant adverse health effects from consumption of marine organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

The Application of SILAC Mouse in Human Body Fluid Proteomics Analysis Reveals Protein Patterns Associated with IgA Nephropathy.

PubMed

Zhao, Shilin; Li, Rongxia; Cai, Xiaofan; Chen, Wanjia; Li, Qingrun; Xing, Tao; Zhu, Wenjie; Chen, Y Eugene; Zeng, Rong; Deng, Yueyi

2013-01-01

Body fluid proteome is the most informative proteome from a medical viewpoint. But the lack of accurate quantitation method for complicated body fluid limited its application in disease research and biomarker discovery. To address this problem, we introduced a novel strategy, in which SILAC-labeled mouse serum was used as internal standard for human serum and urine proteome analysis. The SILAC-labeled mouse serum was mixed with human serum and urine, and multidimensional separation coupled with tandem mass spectrometry (IEF-LC-MS/MS) analysis was performed. The shared peptides between two species were quantified by their SILAC pairs, and the human-only peptides were quantified by mouse peptides with coelution. The comparison for the results from two replicate experiments indicated the high repeatability of our strategy. Then the urine from Immunoglobulin A nephropathy patients treated and untreated was compared by this quantitation strategy. Fifty-three peptides were found to be significantly changed between two groups, including both known diagnostic markers for IgAN and novel candidates, such as Complement C3, Albumin, VDBP, ApoA,1 and IGFBP7. In conclusion, we have developed a practical and accurate quantitation strategy for comparison of complicated human body fluid proteome. The results from such strategy could provide potential disease-related biomarkers for evaluation of treatment.

Classical Optimal Control for Energy Minimization Based On Diffeomorphic Modulation under Observable-Response-Preserving Homotopy.

PubMed

Soley, Micheline B; Markmann, Andreas; Batista, Victor S

2018-06-12

We introduce the so-called "Classical Optimal Control Optimization" (COCO) method for global energy minimization based on the implementation of the diffeomorphic modulation under observable-response-preserving homotopy (DMORPH) gradient algorithm. A probe particle with time-dependent mass m( t;β) and dipole μ( r, t;β) is evolved classically on the potential energy surface V( r) coupled to an electric field E( t;β), as described by the time-dependent density of states represented on a grid, or otherwise as a linear combination of Gaussians generated by the k-means clustering algorithm. Control parameters β defining m( t;β), μ( r, t;β), and E( t;β) are optimized by following the gradients of the energy with respect to β, adapting them to steer the particle toward the global minimum energy configuration. We find that the resulting COCO algorithm is capable of resolving near-degenerate states separated by large energy barriers and successfully locates the global minima of golf potentials on flat and rugged surfaces, previously explored for testing quantum annealing methodologies and the quantum optimal control optimization (QuOCO) method. Preliminary results show successful energy minimization of multidimensional Lennard-Jones clusters. Beyond the analysis of energy minimization in the specific model systems investigated, we anticipate COCO should be valuable for solving minimization problems in general, including optimization of parameters in applications to machine learning and molecular structure determination.

Proteome Analysis of Borrelia burgdorferi Response to Environmental Change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angel, Thomas E.; Luft, Benjamin J.; Yang, Xiaohua

2010-11-02

We examined global changes in protein expression in the B31 strain of Borrelia burgdorferi, in response to two environmental cues (pH and temperature) chosen for their reported similarity to those encountered at different stages of the organism’s life cycle. Multidimensional nano-liquid chromatographic separations coupled with tandem mass spectrometry were used to examine the array of proteins (i.e., the proteome) of B. burgdorferi for different pH and temperature culture conditions. Changes in pH and temperature elicited in vitro adaptations of this spirochete known to cause Lyme disease and led to alterations in protein expression that are associated with increased microbial pathogenesis.more » We identified 1031 proteins that represent 59% of the annotated genome of B. burgdorferi and elucidated a core proteome of 414 proteins that were present in all environmental conditions investigated. Observed changes in protein abundances indicated varied replicon usage, as well as proteome functional distributions between the in vitro cell culture conditions. Surprisingly, the pH and temperature conditions that mimicked B. burgdorferi residing in the gut of a fed tick showed a marked reduction in protein diversity. Additionally, the results provide us with leading candidates for exploring how B. burgdorferi adapts to and is able to survive in a wide variety of environmental conditions and lay a foundation for planned in situ studies of B. burgdorferi isolated from the tick midgut and infected animals.« less

Quantitative Proteomic Analysis of Mouse Embryonic Fibroblasts and Induced Pluripotent Stem Cells Using 16O /18O labeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Xin; Tian, Changhai; Liu, Miao

2012-04-06

Induced pluripotent stem cells (iPSC) hold great promise for regenerative medicine as well as for investigations into the pathogenesis and treatment of various diseases. Understanding of key intracellular signaling pathways and protein targets that control development of iPSC from somatic cells is essential for designing new approaches to improve reprogramming efficiency. Here we report the development and application of an integrated quantitative proteomics platform for investigating differences in protein expressions between mouse embryonic fibroblasts (MEF) and MEF-derived iPSC. This platform consists of 16O/18O labeling, multidimensional peptide separation coupled with tandem mass spectrometry, and data analysis with UNiquant software. Using thismore » platform a total of 2,481 proteins were identified and quantified from the 16O/18O-labeled MEF-iPSC proteome mixtures with a false discovery rate of 0.01. Among them, 218 proteins were significantly upregulated, while 247 proteins were significantly downregulated in iPSC compared to MEF. Many nuclear proteins, including Hdac1, Dnmt1, Pcna, Ccnd1, Smarcc1, and subunits in DNA replication and RNA polymerase II complex were found to be enhanced in iPSC. Protein network analysis revealed that Pcna functions as a hub orchestrating complicated mechanisms including DNA replication, epigenetic inheritance (Dnmt1) and chromatin remodeling (Smarcc1) to reprogram MEF and maintain stemness of iPSC.« less

Combining gas-phase electrophoretic mobility molecular analysis (GEMMA), light scattering, field flow fractionation and cryo electron microscopy in a multidimensional approach to characterize liposomal carrier vesicles

PubMed Central

Gondikas, Andreas; von der Kammer, Frank; Hofmann, Thilo; Marchetti-Deschmann, Martina; Allmaier, Günter; Marko-Varga, György; Andersson, Roland

2017-01-01

For drug delivery, characterization of liposomes regarding size, particle number concentrations, occurrence of low-sized liposome artefacts and drug encapsulation are of importance to understand their pharmacodynamic properties. In our study, we aimed to demonstrate the applicability of nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analyser (nES GEMMA) as a suitable technique for analyzing these parameters. We measured number-based particle concentrations, identified differences in size between nominally identical liposomal samples, and detected the presence of low-diameter material which yielded bimodal particle size distributions. Subsequently, we compared these findings to dynamic light scattering (DLS) data and results from light scattering experiments coupled to Asymmetric Flow-Field Flow Fractionation (AF4), the latter improving the detectability of smaller particles in polydisperse samples due to a size separation step prior detection. However, the bimodal size distribution could not be detected due to method inherent limitations. In contrast, cryo transmission electron microscopy corroborated nES GEMMA results. Hence, gas-phase electrophoresis proved to be a versatile tool for liposome characterization as it could analyze both vesicle size and size distribution. Finally, a correlation of nES GEMMA results with cell viability experiments was carried out to demonstrate the importance of liposome batch-to-batch control as low-sized sample components possibly impact cell viability. PMID:27639623

Enantioselective column coupled electrophoresis employing large bore capillaries hyphenated with tandem mass spectrometry for ultra-trace determination of chiral compounds in complex real samples.

PubMed

Piešťanský, Juraj; Maráková, Katarína; Kovaľ, Marián; Havránek, Emil; Mikuš, Peter

2015-12-01

A new multidimensional analytical approach for the ultra-trace determination of target chiral compounds in unpretreated complex real samples was developed in this work. The proposed analytical system provided high orthogonality due to on-line combination of three different methods (separation mechanisms), i.e. (1) isotachophoresis (ITP), (2) chiral capillary zone electrophoresis (chiral CZE), and (3) triple quadrupole mass spectrometry (QqQ MS). The ITP step, performed in a large bore capillary (800 μm), was utilized for the effective sample pretreatment (preconcentration and matrix clean-up) in a large injection volume (1-10 μL) enabling to obtain as low as ca. 80 pg/mL limits of detection for the target enantiomers in urine matrices. In the chiral CZE step, the different chiral selectors (neutral, ionizable, and permanently charged cyclodextrins) and buffer systems were tested in terms of enantioselectivity and influence on the MS detection response. The performance parameters of the optimized ITP - chiral CZE-QqQ MS method were evaluated according to the FDA guidance for bioanalytical method validation. Successful validation and application (enantioselective monitoring of renally eliminated pheniramine and its metabolite in human urine) highlighted great potential of this chiral approach in advanced enantioselective biomedical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Noise induced quantum effects in photosynthetic complexes

NASA Astrophysics Data System (ADS)

Dorfman, Konstantin; Voronine, Dmitri; Mukamel, Shaul; Scully, Marlan

2012-02-01

Recent progress in coherent multidimensional optical spectroscopy revealed effects of quantum coherence coupled to population leading to population oscillations as evidence of quantum transport. Their description requires reevaluation of the currently used methods and approximations. We identify couplings between coherences and populations as the noise-induced cross-terms in the master equation generated via Agarwal-Fano interference that have been shown earlier to enhance the quantum yield in a photocell. We investigated a broad range of typical parameter regimes, which may be applied to a variety of photosynthetic complexes. We demonstrate that quantum coherence may be induced in photosynthetic complexes under natural conditions of incoherent light from the sun. This demonstrates that a photosynthetic reaction center may be viewed as a biological quantum heat engine that transforms high-energy thermal photon radiation into low entropy electron flux.

Multidimensional Fuel Performance Code: BISON

DOE Office of Scientific and Technical Information (OSTI.GOV)

BISON is a finite element based nuclear fuel performance code applicable to a variety of fuel forms including light water reactor fuel rods, TRISO fuel particles, and metallic rod and plate fuel (Refs. [a, b, c]). It solves the fully-coupled equations of thermomechanics and species diffusion and includes important fuel physics such as fission gas release and material property degradation with burnup. BISON is based on the MOOSE framework (Ref. [d]) and can therefore efficiently solve problems on 1-, 2- or 3-D meshes using standard workstations or large high performance computers. BISON is also coupled to a MOOSE-based mesoscale phasemore » field material property simulation capability (Refs. [e, f]). As described here, BISON includes the code library named FOX, which was developed concurrent with BISON. FOX contains material and behavioral models that are specific to oxide fuels.« less

Density-based clustering: A 'landscape view' of multi-channel neural data for inference and dynamic complexity analysis.

PubMed

Baglietto, Gabriel; Gigante, Guido; Del Giudice, Paolo

2017-01-01

Two, partially interwoven, hot topics in the analysis and statistical modeling of neural data, are the development of efficient and informative representations of the time series derived from multiple neural recordings, and the extraction of information about the connectivity structure of the underlying neural network from the recorded neural activities. In the present paper we show that state-space clustering can provide an easy and effective option for reducing the dimensionality of multiple neural time series, that it can improve inference of synaptic couplings from neural activities, and that it can also allow the construction of a compact representation of the multi-dimensional dynamics, that easily lends itself to complexity measures. We apply a variant of the 'mean-shift' algorithm to perform state-space clustering, and validate it on an Hopfield network in the glassy phase, in which metastable states are largely uncorrelated from memories embedded in the synaptic matrix. In this context, we show that the neural states identified as clusters' centroids offer a parsimonious parametrization of the synaptic matrix, which allows a significant improvement in inferring the synaptic couplings from the neural activities. Moving to the more realistic case of a multi-modular spiking network, with spike-frequency adaptation inducing history-dependent effects, we propose a procedure inspired by Boltzmann learning, but extending its domain of application, to learn inter-module synaptic couplings so that the spiking network reproduces a prescribed pattern of spatial correlations; we then illustrate, in the spiking network, how clustering is effective in extracting relevant features of the network's state-space landscape. Finally, we show that the knowledge of the cluster structure allows casting the multi-dimensional neural dynamics in the form of a symbolic dynamics of transitions between clusters; as an illustration of the potential of such reduction, we define and analyze a measure of complexity of the neural time series.

Supercritical fluid chromatography for lipid analysis in foodstuffs.

PubMed

Donato, Paola; Inferrera, Veronica; Sciarrone, Danilo; Mondello, Luigi

2017-01-01

The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO 2 , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of polymerized liposomes using a combination of dc and cyclical electrical field-flow fractionation.

PubMed

Sant, Himanshu J; Chakravarty, Siddharth; Merugu, Srinivas; Ferguson, Colin G; Gale, Bruce K

2012-10-02

Characterization of polymerized liposomes (PolyPIPosomes) was carried out using a combination of normal dc electrical field-flow fractionation and cyclical electrical field-flow fractionation (CyElFFF) as an analytical technique. The constant nature of the carrier fluid and channel configuration for this technique eliminates many variables associated with multidimensional analysis. CyElFFF uses an oscillating field to induce separation and is performed in the same channel as standard dc electrical field-flow fractionation separation. Theory and experimental methods to characterize nanoparticles in terms of their sizes and electrophoretic mobilities are discussed in this paper. Polystyrene nanoparticles are used for system calibration and characterization of the separation performance, whereas polymerized liposomes are used to demonstrate the applicability of the system to biomedical samples. This paper is also the first to report separation and a higher effective field when CyElFFF is operated at very low applied voltages. The technique is shown to have the ability to quantify both particle size and electrophoretic mobility distributions for colloidal polystyrene nanoparticles and PolyPIPosomes.

Nanoimprinting-induced nanomorphological transition in polymer solar cells: enhanced electrical and optical performance.

PubMed

Jeong, Seonju; Cho, Changsoon; Kang, Hyunbum; Kim, Ki-Hyun; Yuk, Youngji; Park, Jeong Young; Kim, Bumjoon J; Lee, Jung-Yong

2015-03-24

We have investigated the effects of a directly nanopatterned active layer on the electrical and optical properties of inverted polymer solar cells (i-PSCs). The capillary force in confined molds plays a critical role in polymer crystallization and phase separation of the film. The nanoimprinting process induced improved crystallization and multidimensional chain alignment of polymers for more effective charge transfer and a fine phase-separation between polymers and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) to favor exciton dissociation and increase the generation rate of charge transfer excitons. Consequently, the power conversion efficiency with a periodic nanostructure was enhanced from 7.40% to 8.50% and 7.17% to 9.15% in PTB7 and PTB7-Th based i-PSCs, respectively.

Spousal-residence separation among Chinese young couples.

PubMed

Ma, Z; Liaw K-l; Zeng, Y

1996-05-01

The factors affecting the residential separation of spouses in China are examined. "Based on the microdata of the 1987 National Population Survey, we find that the variation in spousal-residence separations among Chinese young couples in the mid-1980s is well explained by personal and household factors within a multivariate model. The separations were aggravated by migrations for the reasons of employment or education. Although marriage migrations reduced the number of separations, those who had been married for a short period of time...were more prone to be separated. It is ironic that the higher a person's level of education, the greater the tendency for them to suffer the pain of spousal-residence separation. Household status could also be a very important factor: the lower the household status of a married individual, the more likely that he (or she) would be separated from their spouse." excerpt

Capillary electrophoresis in two-dimensional separation systems: Techniques and applications.

PubMed

Kohl, Felix J; Sánchez-Hernández, Laura; Neusüß, Christian

2015-01-01

The analysis of complex samples requires powerful separation techniques. Here, 2D chromatographic separation techniques (e.g. LC-LC, GC-GC) are increasingly applied in many fields. Electrophoretic separation techniques show a different selectivity in comparison to LC and GC and very high separation efficiency. Thus, 2D separation systems containing at least one CE-based separation technique are an interesting alternative featuring potentially a high degree of orthogonality. However, the generally small volumes and strong electrical fields in CE require special coupling techniques. These technical developments are reviewed in this work, discussing benefits and drawbacks of offline and online systems. Emphasis is placed on the design of the systems, their coupling, and the detector used. Moreover, the employment of strategies to improve peak capacity, resolution, or sensitivity is highlighted. Various applications of 2D separations with CE are summarized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A reduced basis approach for implementing thermodynamic phase-equilibria information in geophysical and geodynamic studies

NASA Astrophysics Data System (ADS)

Afonso, J. C.; Zlotnik, S.; Diez, P.

2015-12-01

We present a flexible, general and efficient approach for implementing thermodynamic phase equilibria information (in the form of sets of physical parameters) into geophysical and geodynamic studies. The approach is based on multi-dimensional decomposition methods, which transform the original multi-dimensional discrete information into a dimensional-separated representation. This representation has the property of increasing the number of coefficients to be stored linearly with the number of dimensions (opposite to a full multi-dimensional cube requiring exponential storage depending on the number of dimensions). Thus, the amount of information to be stored in memory during a numerical simulation or geophysical inversion is drastically reduced. Accordingly, the amount and resolution of the thermodynamic information that can be used in a simulation or inversion increases substantially. In addition, the method is independent of the actual software used to obtain the primary thermodynamic information, and therefore it can be used in conjunction with any thermodynamic modeling program and/or database. Also, the errors associated with the decomposition procedure are readily controlled by the user, depending on her/his actual needs (e.g. preliminary runs vs full resolution runs). We illustrate the benefits, generality and applicability of our approach with several examples of practical interest for both geodynamic modeling and geophysical inversion/modeling. Our results demonstrate that the proposed method is a competitive and attractive candidate for implementing thermodynamic constraints into a broad range of geophysical and geodynamic studies.

Method for isolating two aquifers in a single borehole

DOEpatents

Burklund, P.W.

1984-01-20

A method for isolating and individually instrumenting separate aquifers within a single borehole is disclosed. A borehole is first drilled from the ground surface, through an upper aquifer, and into a separating confining bed. A casing, having upper and lower sections separated by a coupling collar, is lowered into the borehole. The borehole is grouted in the vicinity of the lower section of the casing. A borehole is then drilled through the grout plug and into a lower aquifer. After the lower aquifer is instrumented, the borehole is grouted back into the lower portion of the casing. Then the upper section of the casing is unscrewed via the coupling collar and removed from the borehole. Finally, instrumentation is added to the upper aquifer and the borehole is appropriately grouted. The coupling collar is designed to have upper right-hand screw threads and lower left-hand screw thread, whereby the sections of the casing can be readily separated.

Method for isolating two aquifers in a single borehole

DOEpatents

Burklund, Patrick W.

1985-10-22

A method for isolating and individually instrumenting separate aquifers within a single borehole. A borehole is first drilled from the ground surface, through an upper aquifer, and into a separating confining bed. A casing, having upper and lower sections separated by a coupling collar, is lowered into the borehole. The borehole is grouted in the vicinity of the lower section of the casing. A borehole is then drilled through the grout plug and into a lower aquifer. After the lower aquifer is instrumented, the borehole is grouted back into the lower portion of the casing. Then the upper section of the casing is unscrewed via the coupling collar and removed from the borehole. Finally, instrumentation is added to the upper aquifer and the borehole is appropriately grouted. The coupling collar is designed to have upper right-hand screw threads and lower left-hand screw thread, whereby the sections of the casing can be readily separated.

Computation of viscous flows over airfoils, including separation, with a coupling approach

NASA Technical Reports Server (NTRS)

Leballeur, J. C.

1983-01-01

Viscous incompressible flows over single or multiple airfoils, with or without separation, were computed using an inviscid flow calculation, with modified boundary conditions, and by a method providing calculation and coupling for boundary layers and wakes, within conditions of strong viscous interaction. The inviscid flow is calculated with a method of singularities, the numerics of which were improved by using both source and vortex distributions over profiles, associated with regularity conditions for the fictitious flows inside of the airfoils. The viscous calculation estimates the difference between viscous flow and inviscid interacting flow, with a direct or inverse integral method, laminar or turbulent, with or without reverse flow. The numerical method for coupling determines iteratively the boundary conditions for the inviscid flow. For attached viscous layers regions, an underrelaxation is locally calculated to insure stability. For separated or separating regions, a special semi-inverse algorithm is used. Comparisons with experiments are presented.

Analysis of reduced monoclonal antibodies using size exclusion chromatography coupled with mass spectrometry

NASA Astrophysics Data System (ADS)

Liu, Hongcheng; Gaza-Bulseco, Georgeen; Chumsae, Chris

2009-12-01

Size-exclusion chromatography (SEC) has been widely used to detect antibody aggregates, monomer, and fragments. SEC coupled to mass spectrometry has been reported to measure the molecular weights of antibody; antibody conjugates, and antibody light chain and heavy chain. In this study, separation of antibody light chain and heavy chain by SEC and direct coupling to a mass spectrometer was further studied. It was determined that employing mobile phases containing acetonitrile, trifluoroacetic acid, and formic acid allowed the separation of antibody light chain and heavy chain after reduction by SEC. In addition, this mobile phase allowed the coupling of SEC to a mass spectrometer to obtain a direct molecular weight measurement. The application of the SEC-MS method was demonstrated by the separation of the light chain and the heavy chain of multiple recombinant monoclonal antibodies. In addition, separation of a thioether linked light chain and heavy chain from the free light chain and the free heavy chain of a recombinant monoclonal antibody after reduction was also achieved. This optimized method provided a separation of antibody light chain and heavy chain based on size and allowed a direct measurement of molecular weights by mass spectrometry. In addition, this method may help to identify peaks eluting from SEC column directly.

Fully coupled approach to modeling shallow water flow, sediment transport, and bed evolution in rivers

NASA Astrophysics Data System (ADS)

Li, Shuangcai; Duffy, Christopher J.

2011-03-01

Our ability to predict complex environmental fluid flow and transport hinges on accurate and efficient simulations of multiple physical phenomenon operating simultaneously over a wide range of spatial and temporal scales, including overbank floods, coastal storm surge events, drying and wetting bed conditions, and simultaneous bed form evolution. This research implements a fully coupled strategy for solving shallow water hydrodynamics, sediment transport, and morphological bed evolution in rivers and floodplains (PIHM_Hydro) and applies the model to field and laboratory experiments that cover a wide range of spatial and temporal scales. The model uses a standard upwind finite volume method and Roe's approximate Riemann solver for unstructured grids. A multidimensional linear reconstruction and slope limiter are implemented, achieving second-order spatial accuracy. Model efficiency and stability are treated using an explicit-implicit method for temporal discretization with operator splitting. Laboratory-and field-scale experiments were compiled where coupled processes across a range of scales were observed and where higher-order spatial and temporal accuracy might be needed for accurate and efficient solutions. These experiments demonstrate the ability of the fully coupled strategy in capturing dynamics of field-scale flood waves and small-scale drying-wetting processes.

Systematic parameter estimation and sensitivity analysis using a multidimensional PEMFC model coupled with DAKOTA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chao Yang; Luo, Gang; Jiang, Fangming

2010-05-01

Current computational models for proton exchange membrane fuel cells (PEMFCs) include a large number of parameters such as boundary conditions, material properties, and numerous parameters used in sub-models for membrane transport, two-phase flow and electrochemistry. In order to successfully use a computational PEMFC model in design and optimization, it is important to identify critical parameters under a wide variety of operating conditions, such as relative humidity, current load, temperature, etc. Moreover, when experimental data is available in the form of polarization curves or local distribution of current and reactant/product species (e.g., O2, H2O concentrations), critical parameters can be estimated inmore » order to enable the model to better fit the data. Sensitivity analysis and parameter estimation are typically performed using manual adjustment of parameters, which is also common in parameter studies. We present work to demonstrate a systematic approach based on using a widely available toolkit developed at Sandia called DAKOTA that supports many kinds of design studies, such as sensitivity analysis as well as optimization and uncertainty quantification. In the present work, we couple a multidimensional PEMFC model (which is being developed, tested and later validated in a joint effort by a team from Penn State Univ. and Sandia National Laboratories) with DAKOTA through the mapping of model parameters to system responses. Using this interface, we demonstrate the efficiency of performing simple parameter studies as well as identifying critical parameters using sensitivity analysis. Finally, we show examples of optimization and parameter estimation using the automated capability in DAKOTA.« less

Comprehensive two-dimensional gas chromatography and food sensory properties: potential and challenges.

PubMed

Cordero, Chiara; Kiefl, Johannes; Schieberle, Peter; Reichenbach, Stephen E; Bicchi, Carlo

2015-01-01

Modern omics disciplines dealing with food flavor focus the analytical efforts on the elucidation of sensory-active compounds, including all possible stimuli of multimodal perception (aroma, taste, texture, etc.) by means of a comprehensive, integrated treatment of sample constituents, such as physicochemical properties, concentration in the matrix, and sensory properties (odor/taste quality, perception threshold). Such analyses require detailed profiling of known bioactive components as well as advanced fingerprinting techniques to catalog sample constituents comprehensively, quantitatively, and comparably across samples. Multidimensional analytical platforms support comprehensive investigations required for flavor analysis by combining information on analytes' identities, physicochemical behaviors (volatility, polarity, partition coefficient, and solubility), concentration, and odor quality. Unlike other omics, flavor metabolomics and sensomics include the final output of the biological phenomenon (i.e., sensory perceptions) as an additional analytical dimension, which is specifically and exclusively triggered by the chemicals analyzed. However, advanced omics platforms, which are multidimensional by definition, pose challenging issues not only in terms of coupling with detection systems and sample preparation, but also in terms of data elaboration and processing. The large number of variables collected during each analytical run provides a high level of information, but requires appropriate strategies to exploit fully this potential. This review focuses on advances in comprehensive two-dimensional gas chromatography and analytical platforms combining two-dimensional gas chromatography with olfactometry, chemometrics, and quantitative assays for food sensory analysis to assess the quality of a given product. We review instrumental advances and couplings, automation in sample preparation, data elaboration, and a selection of applications.

Depressive symptoms postpartum among parents are associated with marital separation: a Swedish cohort study.

PubMed

Kerstis, Birgitta; Berglund, Anders; Engström, Gabriella; Edlund, Birgitta; Sylvén, Sara; Aarts, Clara

2014-11-01

To study whether there is an association between dyadic consensus, depressive symptoms, and parental stress during early parenthood and marital separation 6-8 years after childbirth, among couples in Sweden. At baseline, 393 couples were included. The couples answered three questionnaires, including: Dyadic consensus at 1 week post-partum, depressive symptoms at 3 months post-partum and parental stress at 18 months post-partum. The parents' addresses were followed up after 6-8 years, to study the marital separation rate. We found, 6-8 years after childbirth, that 20% of study couples were separated. Separation was associated with less dyadic consensus (mothers p < 0.001; fathers p < 0.001), depressive symptoms (mothers p = 0.022; fathers p = 0.041) and parental stress (mothers p = 0.002; fathers p = 0.040). The hazard ratio (HR) for marital separation was related to dyadic consensus for fathers (HR 0.51; 95% CI 0.28-0.92), depressive symptoms for mothers (HR 1.69; 95% CI 1.01-2.84) and fathers (HR 1.92; 95% CI 1.12-3.28), and the mother's parental stress (HR 2.16; 95% CI 1.14-4.07). Understanding how dyadic consensus, depressive symptoms and parental stress are associated with marital separation is important for health professionals it could be useful in developing interventions to provide parents with adequate support during pregnancy and early parenthood this knowledge is also important for the public parents should get support in pregnancy and while bringing up children, which may help prevent marital separation and optimize conditions for the children. © 2014 the Nordic Societies of Public Health.

Multiphysics Modelling of Sodium Sulfur Battery

NASA Astrophysics Data System (ADS)

Mason, Jerry Hunter

Due to global climate change and the desire to decrease greenhouse gas emissions, large scale energy storage has become a critical issue. Renewable energy sources such as wind and solar will not be a viable energy source unless the storage problem is solved. One of the practical and cost effective solutions for this problem is sodium sulfur batteries. These batteries are comprised of liquid electrode materials suspended in porous media and operate at relatively high temperatures (>300°C). The sodium anode and the sulfur/sodium-polysulfide cathode are separated by a solid electrolyte made of beta-alumina or NASICON material. Due to the use of porous materials in the electrodes, capillary pressure and the combination of capillary action and gravity become important. Capillary pressure has a strong dependence on the wetting phase (liquid electrode material) saturation; therefore sharp concentration gradients can occur between the inert gas and the electrode liquid, especially within the cathode. These concentration gradients can have direct impacts on the electrodynamics of the battery as they may produce areas of high electrical potential variation, which can decrease efficiency and even cause failures. Then, thermal management also becomes vital since the electrochemistry and material properties are sensitive to temperature gradients. To investigate these phenomena in detail and to attempt to improve upon battery design a multi-dimensional, multi-phase code has been developed and validated in this study. Then a porous media flow model is implemented. Transport equations for charge, mass and heat are solved in a time marching fashion using finite volume method. Material properties are calculated and updated as a function of time. The porous media model is coupled with the continuity equation and a separate diffusion equation for the liquid sodium in the melt. The total mass transport model is coupled with charge transport via Faraday's law. Results show that overpotential is significantly higher in the porous region of the cathode as was predicted by models in the literature. Overpotential is also high on the electrolyte surface and wall. Alternative electrode configurations with high resistive layers recommended by previous researchers also produce areas of high potential gradient. New electrode designs including conductivity gradients and porous media property variations are simulated and compared to previous designs and then recommendations are made for optimum cell operating conditions.

Development of a 45kpsi ultrahigh pressure liquid chromatography instrument for gradient separations of peptides using long microcapillary columns and sub-2μm particles.

PubMed

Grinias, Kaitlin M; Godinho, Justin M; Franklin, Edward G; Stobaugh, Jordan T; Jorgenson, James W

2016-10-21

Commercial chromatographic instrumentation for bottom-up proteomics is often inadequate to resolve the number of peptides in many samples. This has inspired a number of complex approaches to increase peak capacity, including various multidimensional approaches, and reliance on advancements in mass spectrometry. One-dimensional reversed phase separations are limited by the pressure capabilities of commercial instruments and prevent the realization of greater separation power in terms of speed and resolution inherent to smaller sorbents and ultrahigh pressure liquid chromatography. Many applications with complex samples could benefit from the increased separation performance of long capillary columns packed with sub-2μm sorbents. Here, we introduce a system that operates at a constant pressure and is capable of separations at pressures up to 45kpsi. The system consists of a commercially available capillary liquid chromatography instrument, for sample management and gradient creation, and is modified with a storage loop and isolated pneumatic amplifier pump for elevated separation pressure. The system's performance is assessed with a complex peptide mixture and a range of microcapillary columns packed with sub-2μm C18 particles. Copyright © 2016 Elsevier B.V. All rights reserved.

Multidimensional Diagnostic Criteria for Chronic Pain: Introduction to the ACTTION-American Pain Society Pain Taxonomy (AAPT).

PubMed

Dworkin, Robert H; Bruehl, Stephen; Fillingim, Roger B; Loeser, John D; Terman, Gregory W; Turk, Dennis C

2016-09-01

A variety of approaches have been used to develop diagnostic criteria for chronic pain. The published evidence of the reliability and validity of existing diagnostic criteria is limited, and these criteria have typically not been used in clinical practice. The availability of a widely accepted, consistently applied, and evidence-based taxonomy of diagnostic criteria would improve the quality of clinical research on chronic pain and would be of great value in clinical practice. To address the need for evidence-based diagnostic criteria for the major chronic pain conditions, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the US Food and Drug Administration and the American Pain Society (APS) have collaborated on the development of the ACTTION-APS Pain Taxonomy (AAPT). AAPT provides a multidimensional framework that is applied systematically in the development of diagnostic criteria. This article (1) describes the background and rationale for AAPT; (2) presents the AAPT taxonomy and the specific conditions for which diagnostic criteria have been developed (to be published separately); (3) briefly reviews the 5 dimensions that constitute the AAPT multidimensional framework and describes the 7 accompanying articles that discuss these dimensions and other important issues involving AAPT; and (4) provides an overview of next steps, specifically, the general processes by which the initial set of diagnostic criteria (for which the evidence base has been drawn from the literature, systematic reviews, and secondary analyses of existing databases) will undergo additional assessments of reliability and validity. To address the need for evidence-based diagnostic criteria for the major chronic pain conditions, the AAPT provides a multidimensional framework that is applied systematically in the development of diagnostic criteria. The long-term objective of AAPT is to advance the scientific understanding of chronic pain and its treatment. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Superfast algorithms of multidimensional discrete k-wave transforms and Volterra filtering based on superfast radon transform

NASA Astrophysics Data System (ADS)

Labunets, Valeri G.; Labunets-Rundblad, Ekaterina V.; Astola, Jaakko T.

2001-12-01

Fast algorithms for a wide class of non-separable n-dimensional (nD) discrete unitary K-transforms (DKT) are introduced. They need less 1D DKTs than in the case of the classical radix-2 FFT-type approach. The method utilizes a decomposition of the nD K-transform into the product of a new nD discrete Radon transform and of a set of parallel/independ 1D K-transforms. If the nD K-transform has a separable kernel (e.g., the case of the discrete Fourier transform) our approach leads to decrease of multiplicative complexity by the factor of n comparing to the classical row/column separable approach. It is well known that an n-th order Volterra filter of one dimensional signal can be evaluated by an appropriate nD linear convolution. This work describes new superfast algorithm for Volterra filtering. New approach is based on the superfast discrete Radon and Nussbaumer polynomial transforms.

Phase separation like dynamics during Myxococcus xanthus fruiting body formation

NASA Astrophysics Data System (ADS)

Liu, Guannan; Thutupalli, Shashi; Wigbers, Manon; Shaevitz, Joshua

2015-03-01

Collective motion exists in many living organisms as an advantageous strategy to help the entire group with predation, forage, and survival. However, the principles of self-organization underlying such collective motions remain unclear. During various developmental stages of the soil-dwelling bacterium, Myxococcus xanthus, different types of collective motions are observed. In particular, when starved, M. xanthus cells eventually aggregate together to form 3-dimensional structures (fruiting bodies), inside which cells sporulate in response to the stress. We study the fruiting body formation process as an out of equilibrium phase separation process. As local cell density increases, the dynamics of the aggregation M. xanthus cells switch from a spatio-temporally random process, resembling nucleation and growth, to an emergent pattern formation process similar to a spinodal decomposition. By employing high-resolution microscopy and a video analysis system, we are able to track the motion of single cells within motile collective groups, while separately tuning local cell density, cell velocity and reversal frequency, probing the multi-dimensional phase space of M. xanthus development.

Evolutionary multidimensional access architecture featuring cost-reduced components

NASA Astrophysics Data System (ADS)

Farjady, Farsheed; Parker, Michael C.; Walker, Stuart D.

1998-12-01

We describe a three-stage wavelength-routed optical access network, utilizing coarse passband-flattened arrayed- waveguide grating routers. An N-dimensional addressing strategy enables 6912 customers to be bi-directionally addressed with multi-Gb/s data using only 24 wavelengths spaced by 1.6 nm. Coarse wavelength separation allows use of increased tolerance WDM components at the exchange and customer premises. The architecture is designed to map onto standard access network topologies, allowing elegant upgradability from legacy PON infrastructures at low cost. Passband-flattening of the routers is achieved through phase apodization.

Sound transmission through stiffened double-panel structures lined with elastic porous materials

NASA Astrophysics Data System (ADS)

Mathur, Gopal P.; Tran, Boi N.; Bolton, J. S.; Shiau, Nae-Ming

This paper presents transmission loss prediction models for a periodically stiffened panel and stiffened double-panel structures using the periodic structure theory. The inter-panel cavity in the double-panels structures can be modeled as being separated by an airspace or filled with an elastic porous layer in various configurations. The acoustic behavior of elastic porous layer is described by a theory capable of accounting fully for multi-dimensional wave propagation in such materials. The predicted transmission loss of a single stiffened panel is compared with the measured data.

Dual-band frequency selective surface with large band separation and stable performance

NASA Astrophysics Data System (ADS)

Zhou, Hang; Qu, Shao-Bo; Peng, Wei-Dong; Lin, Bao-Qin; Wang, Jia-Fu; Ma, Hua; Zhang, Jie-Qiu; Bai, Peng; Wang, Xu-Hua; Xu, Zhuo

2012-05-01

A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations.

Modern separation techniques coupled to high performance mass spectrometry for glycolipid analysis.

PubMed

Sarbu, Mirela; Zamfir, Alina Diana

2018-01-21

Glycolipids (GLs), involved in biological processes and pathologies, such as viral, neurodegenerative and oncogenic transformations are in the focus of research related to method development for structural analysis. This review highlights modern separation techniques coupled to mass spectrometry (MS) for the investigation of GLs from various biological matrices. First section is dedicated to methods, which, although provide the separation in a non-liquid phase, are able to supply important data on the composition of complex mixtures. While classical thin layer chromatography (TLC) is useful for MS analyses of the fractionated samples, ultramodern ion mobility (IMS) characterized by high reproducibility facilitates to discover minor species and to apply low sample amounts, in addition to providing conformational separation with isomer discrimination. Second section highlights the advantages, applications and limitations of liquid-based separation techniques such as high performance liquid chromatography (HPLC) and hydrophilic interaction liquid chromatography (HILIC) in direct or indirect coupling to MS for glycolipidomics surveys. The on- and off-line capillary electrophoresis (CE) MS, offering a remarkable separation efficiency of GLs is also presented and critically assessed from the technical and application perspective in the final part of the review. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

We can work it out: age differences in relational pronouns, physiology, and behavior in marital conflict.

PubMed

Seider, Benjamin H; Hirschberger, Gilad; Nelson, Kristin L; Levenson, Robert W

2009-09-01

This study examined the relationship that personal pronouns spoken during a marital conversation have with the emotional qualities of those interactions and with marital satisfaction. Middle-aged and older couples (N = 154) engaged in a 15-min conflict conversation during which physiology and emotional behavior were continuously monitored. Verbatim transcripts of the conversations were coded into 2 lexical categories: (a) we-ness (we-words), pronouns that focus on the couple; (b) separateness (me/you-words), pronouns that focus on the individual spouses. Analyses revealed that greater we-ness was associated with a number of desirable qualities of the interaction (lower cardiovascular arousal, more positive and less negative emotional behavior), whereas greater separateness was associated with a less desirable profile (more negative emotional behavior, lower marital satisfaction). In terms of age differences, older couples used more we-ness words than did middle-aged couples. Further, the associations between separateness and marital satisfaction were strongest for older wives. These findings indicate that the emotional aspects of marital quality are expressed in the natural language of couples engaged in conversation. (c) 2009 APA, all rights reserved.

We can work it out: Age differences in relational pronouns, physiology, and behavior in marital conflict

PubMed Central

Seider, Benjamin H.; Hirschberger, Gilad; Nelson, Kristin L.; Levenson, Robert W.

2009-01-01

This study examined the relationship that personal pronouns spoken during a marital conversation have with the emotional qualities of those interactions and with marital satisfaction. Middle-aged and older couples (N=154) engaged in a 15-minute conflict conversation during which physiology and emotional behavior were continuously monitored. Verbatim transcripts of the conversations were coded into two lexical categories: (a) We-ness (we-words): pronouns that focus on the couple; (b) Separateness (Me/You words): pronouns that focus on the individual spouses. Analyses revealed that greater We-ness was associated with a number of desirable qualities of the interaction (lower cardiovascular arousal, more positive and less negative emotional behavior), whereas, greater Separateness was associated with a less desirable profile (more negative emotional behavior, lower marital satisfaction). In terms of age differences, older couples used more We-ness than middle-aged couples. Further, the associations between Separateness and marital satisfaction were strongest for older wives. These findings indicate that the emotional aspects of marital quality are expressed in the natural language of couples engaged in conversation. PMID:19739916

LC-IMS-MS Feature Finder: detecting multidimensional liquid chromatography, ion mobility and mass spectrometry features in complex datasets.

PubMed

Crowell, Kevin L; Slysz, Gordon W; Baker, Erin S; LaMarche, Brian L; Monroe, Matthew E; Ibrahim, Yehia M; Payne, Samuel H; Anderson, Gordon A; Smith, Richard D

2013-11-01

The addition of ion mobility spectrometry to liquid chromatography-mass spectrometry experiments requires new, or updated, software tools to facilitate data processing. We introduce a command line software application LC-IMS-MS Feature Finder that searches for molecular ion signatures in multidimensional liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) data by clustering deisotoped peaks with similar monoisotopic mass, charge state, LC elution time and ion mobility drift time values. The software application includes an algorithm for detecting and quantifying co-eluting chemical species, including species that exist in multiple conformations that may have been separated in the IMS dimension. LC-IMS-MS Feature Finder is available as a command-line tool for download at http://omics.pnl.gov/software/LC-IMS-MS_Feature_Finder.php. The Microsoft.NET Framework 4.0 is required to run the software. All other dependencies are included with the software package. Usage of this software is limited to non-profit research to use (see README). rds@pnnl.gov. Supplementary data are available at Bioinformatics online.

Multidimensional analysis of fast-spectrum material replacement measurements for systematic estimation of cross section uncertainties

NASA Technical Reports Server (NTRS)

Klann, P. G.; Lantz, E.; Mayo, W. T.

1973-01-01

A series of central core and core-reflector interface sample replacement experiments for 16 materials performed in the NASA heavy-metal-reflected, fast spectrum critical assembly (NCA) were analyzed in four and 13 groups using the GAM 2 cross-section set. The individual worths obtained by TDSN and DOT multidimensional transport theory calculations showed significant differences from the experimental results. These were attributed to cross-section uncertainties in the GAM 2 cross sections. Simultaneous analysis of the measured and calculated sample worths permitted separation of the worths into capture and scattering components which systematically provided fast spectrum averaged correction factors to the magnitudes of the GAM 2 absorption and scattering cross sections. Several Los Alamos clean critical assemblies containing Oy, Ta, and Mo as well as one of the NCA compositions were reanalyzed using the corrected cross sections. In all cases the eigenvalues were significantly improved and were recomputed to within 1 percent of the experimental eigenvalue. A comparable procedure may be used for ENDF cross sections when these are available.

ITQ-54: a multi-dimensional extra-large pore zeolite with 20 × 14 × 12-ring channels

DOE PAGES

Jiang, Jiuxing; Yun, Yifeng; Zou, Xiaodong; ...

2015-01-01

A multi-dimensional extra-large pore silicogermanate zeolite, named ITQ-54, has been synthesised by in situ decomposition of the N,N-dicyclohexylisoindolinium cation into the N-cyclohexylisoindolinium cation. Its structure was solved by 3D rotation electron diffraction (RED) from crystals of ca. 1 μm in size. The structure of ITQ-54 contains straight intersecting 20 × 14 × 12-ring channels along the three crystallographic axes and it is one of the few zeolites with extra-large channels in more than one direction. ITQ-54 has a framework density of 11.1 T atoms per 1000 Å 3, which is one of the lowest among the known zeolites. ITQ-54 wasmore » obtained together with GeO 2 as an impurity. A heavy liquid separation method was developed and successfully applied to remove this impurity from the zeolite. ITQ-54 is stable up to 600 °C and exhibits permanent porosity. The structure was further refined using powder X-ray diffraction (PXRD) data for both as-made and calcined samples.« less

The multidimensional nature of ageism: construct validity and group differences.

PubMed

Rupp, Deborah E; Vodanovich, Stephen J; Credé, Marcus

2005-06-01

The authors investigated the factor structure and construct validity of the Fraboni Scale of Ageism and the age and gender differences in ageism scores. Confirmatory factor analyses supported the multidimensional nature of FSA scores and generally corroborated the initial factor structure reported by M. Fraboni, with some notable exceptions. Essentially, the present findings were aligned with theoretical models of ageism that emphasize both cognitive facets and affective facets. That is, on the basis of their factor analytic findings, the authors redefined Fraboni's original factors of Antilocution, Avoidance, and Discrimination as Stereotypes, Separation, and Affective Attitudes, respectively, because of the clustering of items within factors. The revised 3-factor structure accounted for 36.4% of the variance in FSA scores. FSA factor scores significantly related to other scores from other measures of age-related attitudes, with higher correlations among factors that were similar in terms of their cognitive nature versus their affective nature. Finally, younger individuals and men had significantly higher ageism scores on the FSA than older individuals and women. The authors discussed the importance of adequately assessing ageism, with particular emphasis devoted to the understanding of age bias.

Emotional competencies in geriatric nursing: empirical evidence from a computer based large scale assessment calibration study.

PubMed

Kaspar, Roman; Hartig, Johannes

2016-03-01

The care of older people was described as involving substantial emotion-related affordances. Scholars in vocational training and nursing disagree whether emotion-related skills could be conceptualized and assessed as a professional competence. Studies on emotion work and empathy regularly neglect the multidimensionality of these phenomena and their relation to the care process, and are rarely conclusive with respect to nursing behavior in practice. To test the status of emotion-related skills as a facet of client-directed geriatric nursing competence, 402 final-year nursing students from 24 German schools responded to a 62-item computer-based test. 14 items were developed to represent emotion-related affordances. Multi-dimensional IRT modeling was employed to assess a potential subdomain structure. Emotion-related test items did not form a separate subdomain, and were found to be discriminating across the whole competence continuum. Tasks concerning emotion work and empathy are reliable indicators for various levels of client-directed nursing competence. Claims for a distinct emotion-related competence in geriatric nursing, however, appear excessive with a process-oriented perspective.

Knowledge-based nonuniform sampling in multidimensional NMR.

PubMed

Schuyler, Adam D; Maciejewski, Mark W; Arthanari, Haribabu; Hoch, Jeffrey C

2011-07-01

The full resolution afforded by high-field magnets is rarely realized in the indirect dimensions of multidimensional NMR experiments because of the time cost of uniformly sampling to long evolution times. Emerging methods utilizing nonuniform sampling (NUS) enable high resolution along indirect dimensions by sampling long evolution times without sampling at every multiple of the Nyquist sampling interval. While the earliest NUS approaches matched the decay of sampling density to the decay of the signal envelope, recent approaches based on coupled evolution times attempt to optimize sampling by choosing projection angles that increase the likelihood of resolving closely-spaced resonances. These approaches employ knowledge about chemical shifts to predict optimal projection angles, whereas prior applications of tailored sampling employed only knowledge of the decay rate. In this work we adapt the matched filter approach as a general strategy for knowledge-based nonuniform sampling that can exploit prior knowledge about chemical shifts and is not restricted to sampling projections. Based on several measures of performance, we find that exponentially weighted random sampling (envelope matched sampling) performs better than shift-based sampling (beat matched sampling). While shift-based sampling can yield small advantages in sensitivity, the gains are generally outweighed by diminished robustness. Our observation that more robust sampling schemes are only slightly less sensitive than schemes highly optimized using prior knowledge about chemical shifts has broad implications for any multidimensional NMR study employing NUS. The results derived from simulated data are demonstrated with a sample application to PfPMT, the phosphoethanolamine methyltransferase of the human malaria parasite Plasmodium falciparum.

Why do Ladybugs Smell Bad? In-vivo Quantification of Odorous Insect Kairomones with SPME and Multidimensional GC-MS-Olfactometry

NASA Astrophysics Data System (ADS)

Cai, Lingshuang; Koziel, Jacek A.; O'Neal, Matthew E.

2009-05-01

Winemakers, small fruit growers, and homeowners are concerned with noxious compounds released by multicolored Asian ladybird beetles (Harmonia axyridis, Coleoptera: Coccinellidae). New method based on headspace solid phase microextraction (HS-SPME) coupled with multidimensional gas chromatography mass spectrometry—olfactometry (MDGC-MS-O) system was developed for extraction, isolation and simultaneous identification of compounds responsible for the characteristic odor of live H. axyridis. Four methoxypyrazines (MPs) were identified in headspace volatiles of live H. axyridis as those responsible for the characteristic odor: 2, 5-dimethy1-3-methoxypyrazine (DMMP), 2-isopropy1-3-methoxypyrazine (IPMP), 2-sec-buty1-3-methoxypyrazine (SBMP), and 2-isobuty1-3-methoxypyrazine (IBMP). To the best of our knowledge this is the first report of H. axyridis releasing DMMP and the first report of this compound being a component of the H. axyridis characteristic odor. Quantification of three MPs (IPMP, SBMP and IBMP) emitted from live H. axyridis were performed using external calibration with HS-SPME and direct injections. A linear relationship (R2>0.9958 for all 3 MPs) between MS response and concentration of standard was observed over a concentration range from 0.1 ng L-1 to 0.05 μg L-1 for HS-SPME-GC-MS. The method detection limits (MDL) based on multidimensional GC-MS approach for three MPs were estimated to be between 0.020 ng L-1. to 0.022 ng L-1. This methodology is applicable for in vivo determination of odor-causing chemicals associated with emissions of volatiles from insects.

A Multidimensional B-Spline Correction for Accurate Modeling Sugar Puckering in QM/MM Simulations.

PubMed

Huang, Ming; Dissanayake, Thakshila; Kuechler, Erich; Radak, Brian K; Lee, Tai-Sung; Giese, Timothy J; York, Darrin M

2017-09-12

The computational efficiency of approximate quantum mechanical methods allows their use for the construction of multidimensional reaction free energy profiles. It has recently been demonstrated that quantum models based on the neglect of diatomic differential overlap (NNDO) approximation have difficulty modeling deoxyribose and ribose sugar ring puckers and thus limit their predictive value in the study of RNA and DNA systems. A method has been introduced in our previous work to improve the description of the sugar puckering conformational landscape that uses a multidimensional B-spline correction map (BMAP correction) for systems involving intrinsically coupled torsion angles. This method greatly improved the adiabatic potential energy surface profiles of DNA and RNA sugar rings relative to high-level ab initio methods even for highly problematic NDDO-based models. In the present work, a BMAP correction is developed, implemented, and tested in molecular dynamics simulations using the AM1/d-PhoT semiempirical Hamiltonian for biological phosphoryl transfer reactions. Results are presented for gas-phase adiabatic potential energy surfaces of RNA transesterification model reactions and condensed-phase QM/MM free energy surfaces for nonenzymatic and RNase A-catalyzed transesterification reactions. The results show that the BMAP correction is stable, efficient, and leads to improvement in both the potential energy and free energy profiles for the reactions studied, as compared with ab initio and experimental reference data. Exploration of the effect of the size of the quantum mechanical region indicates the best agreement with experimental reaction barriers occurs when the full CpA dinucleotide substrate is treated quantum mechanically with the sugar pucker correction.

Living Together Apart in France and the United States

PubMed Central

Martin, Claude; Cherlin, Andrew; Cross-Barnet, Caitlin

2014-01-01

Union formation involves a number of stages, as does union dissolution, and new couples often spend an initial period in a non-cohabiting intimate relationship. Yet while certain couples never share the same dwelling, “living apart together”1 has not developed widely as a long-term lifestyle option. Claude Martin in France, and Andrew Cherlin and Caitlin Cross-Barnet in the United States have studied a symmetrical phenomenon, that of couples who continue to live together while considering themselves to be separated. In this article, they draw together their analyses to describe an arrangement which, while marginal, reveals situations where residential separation is not possible, either because of the need to keep up appearances, often for the children’s sake, or because total separation is too frightening or living in separate homes is unaffordable. Beyond the differences between the two countries and the two survey fields, the authors analyse the ways in which persons who “live together apart” describe their loveless relationship that has led to explicit conjugal separation within a shared home. PMID:25170338

Optical Properties of Vibronically Coupled Cy3 Dimers on DNA Scaffolds.

PubMed

Cunningham, Paul D; Kim, Young C; Díaz, Sebastián A; Buckhout-White, Susan; Mathur, Divita; Medintz, Igor L; Melinger, Joseph S

2018-05-17

We examine the effect of electronic coupling on the optical properties of Cy3 dimers attached to DNA duplexes as a function of base pair (bp) separation using steady-state and time-resolved spectroscopy. For close Cy3-Cy3 separations, 0 and 1 bp between dyes, intermediate to strong electronic coupling is revealed by modulation of the absorption and fluorescence properties including spectral band shape, peak wavelength, and excited-state lifetime. Using a vibronic exciton model, we estimate coupling strengths of 150 and 266 cm -1 for the 1 and 0 bp separations, respectively, which are comparable to those found in natural light-harvesting complexes. For the strongest electronic coupling (0 bp separation), we observe that the absorption band shape is strongly affected by the base pairs that surround the dyes, where more strongly hydrogen-bonded G-C pairs produce a red-shifted absorption spectrum consistent with a J-type dimer. This effect is studied theoretically using molecular dynamics simulation, which predicts an in-line dye configuration that is consistent with the experimental J-type spectrum. When the Cy3 dimers are in a standard aqueous buffer, the presence of relatively strong electronic coupling is accompanied by decreased fluorescence lifetime, suggesting that it promotes nonradiative relaxation in cyanine dyes. However, we show that the use of a viscous solvent can suppress this nonradiative recombination and thereby restore the dimer fluorescent emission. Ultrafast transient absorption measurements of Cy3 dimers in both standard aqueous buffer and viscous glycerol buffer suggest that sufficiently strong electronic coupling increases the probability of excited-state relaxation through a dark state that is related to Cy3 torsional motion.

Parenthood and separation in couples 6 years after their first infertility consultation.

PubMed

Ferreira, Magali; Sanchez, Emeline Teillet; Gatimel, Nicolas; Fajau, Carole; Lesourd, Florence; Bujan, Louis; Mieusset, Roger; Parinaud, Jean; Leandri, Roger

2016-03-01

To evaluate the percentage of couples achieving parenthood and the rate of separation 6 years after their first consultation for infertility. Epidemiological study in the reproductive medicine department of a French university hospital. All first consulting couples (FCC) who had their first infertility consultation in the department in 2007 were contacted by phone and asked to respond to a questionnaire concerning their infertility treatments, parenthood and marital status 6 years after their first consultation. Of the 685 FCC, 94 could not be contacted, 34 refused to respond and 557 (86%) answered the questionnaire. Of 557 FCC who have responded, 361 (65%) have achieved parenthood: 166 (46%) after treatment, 98 (27%) after spontaneous conception, 38 (11%) after both spontaneous and treatment-induced conception and 59 (16%) through adoption. Parenthood was not influenced either by the causes or duration of infertility. Separation occurred in 53 (9.5%) of FCC, mainly in those without any children (28% vs 4% in FCC with at least one child; P<.0001). Six years after their primary consultation, 25% of couples remained childless and 28% of them were separated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Multidimensional poverty, household environment and short-term morbidity in India.

PubMed

Dehury, Bidyadhar; Mohanty, Sanjay K

2017-01-01

Using the unit data from the second round of the Indian Human Development Survey (IHDS-II), 2011-2012, which covered 42,152 households, this paper examines the association between multidimensional poverty, household environmental deprivation and short-term morbidities (fever, cough and diarrhoea) in India. Poverty is measured in a multidimensional framework that includes the dimensions of education, health and income, while household environmental deprivation is defined as lack of access to improved sanitation, drinking water and cooking fuel. A composite index combining multidimensional poverty and household environmental deprivation has been computed, and households are classified as follows: multidimensional poor and living in a poor household environment, multidimensional non-poor and living in a poor household environment, multidimensional poor and living in a good household environment and multidimensional non-poor and living in a good household environment. Results suggest that about 23% of the population belonging to multidimensional poor households and living in a poor household environment had experienced short-term morbidities in a reference period of 30 days compared to 20% of the population belonging to multidimensional non-poor households and living in a poor household environment, 19% of the population belonging to multidimensional poor households and living in a good household environment and 15% of the population belonging to multidimensional non-poor households and living in a good household environment. Controlling for socioeconomic covariates, the odds of short-term morbidity was 1.47 [CI 1.40-1.53] among the multidimensional poor and living in a poor household environment, 1.28 [CI 1.21-1.37] among the multidimensional non-poor and living in a poor household environment and 1.21 [CI 1.64-1.28] among the multidimensional poor and living in a good household environment compared to the multidimensional non-poor and living in a good household environment. Results are robust across states and hold good for each of the three morbidities: fever, cough and diarrhoea. This establishes that along with poverty, household environmental conditions have a significant bearing on short-term morbidities in India. Public investment in sanitation, drinking water and cooking fuel can reduce the morbidity and improve the health of the population.

Alcoholism and Timing of Separation in Parents: Findings in a Midwestern Birth Cohort

PubMed Central

Waldron, Mary; Bucholz, Kathleen K.; Lynskey, Michael T.; Madden, Pamela A. F.; Heath, Andrew C.

2013-01-01

Objective: We examined history of alcoholism and occurrence and timing of separation in parents of a female twin cohort. Method: Parental separation (never-together; never-married cohabitants who separated; married who separated) was predicted from maternal and paternal alcoholism in 326 African ancestry (AA) and 1,849 European/other ancestry (EA) families. Broad (single-informant, reported in abstract) and narrow (self-report or two-informant) measures of alcoholism were compared. Results: Parental separation was more common in families with parental alcoholism: By the time twins were 18 years of age, parents had separated in only 24% of EA families in which neither parent was alcoholic, contrasted with 58% of families in which only the father was (father-only), 61% of families in which only the mother was (mother-only), and 75% in which both parents were alcoholic (two-parent); corresponding AA percentages were 59%, 71%, 82%, and 86%, respectively. Maternal alcoholism was more common in EA never-together couples (mother-only: odds ratio [OR] = 5.95; two parent: OR = 3.69). In ever-together couples, alcoholism in either parent predicted elevated risk of separation, with half of EA relationships ending in separation within 12 years of twins’ birth for father-only families, 9 years for mother-only families, and 4 years for both parents alcoholic; corresponding median survival times for AA couples were 9, 4, and 2 years, respectively. EA maternal alcoholism was especially strongly associated with separation in the early postnatal years (mother-only: birth—5 years, hazard ratio [HR] = 4.43; 6 years on, HR = 2.52; two-parent: HRs = 5.76, 3.68, respectively). Conclusions: Parental separation is a childhood environmental exposure that is more common in children of alcoholics, with timing of separation highly dependent on alcoholic parent gender. PMID:23384382

Alcoholism and timing of separation in parents: findings in a midwestern birth cohort.

PubMed

Waldron, Mary; Bucholz, Kathleen K; Lynskey, Michael T; Madden, Pamela A F; Heath, Andrew C

2013-03-01

We examined history of alcoholism and occurrence and timing of separation in parents of a female twin cohort. Parental separation (never-together; never-married cohabitants who separated; married who separated) was predicted from maternal and paternal alcoholism in 326 African ancestry (AA) and 1,849 European/ other ancestry (EA) families. Broad (single-informant, reported in abstract) and narrow (self-report or two-informant) measures of alcoholism were compared. Parental separation was more common in families with parental alcoholism: By the time twins were 18 years of age, parents had separated in only 24% of EA families in which neither parent was alcoholic, contrasted with 58% of families in which only the father was (father-only), 61% of families in which only the mother was (mother-only), and 75% in which both parents were alcoholic (two-parent); corresponding AA percentages were 59%, 71%, 82%, and 86%, respectively. Maternal alcoholism was more common in EA nevertogether couples (mother-only: odds ratio [OR] = 5.95; two parent: OR = 3.69). In ever-together couples, alcoholism in either parent predicted elevated risk of separation, with half of EA relationships ending in separation within 12 years of twins' birth for father-only families, 9 years for mother-only families, and 4 years for both parents alcoholic; corresponding median survival times for AA couples were 9, 4, and 2 years, respectively. EA maternal alcoholism was especially strongly associated with separation in the early postnatal years (mother-only: birth-5 years, hazard ratio [HR] = 4.43; 6 years on, HR = 2.52; two-parent: HRs = 5.76, 3.68, respectively). Parental separation is a childhood environmental exposure that is more common in children of alcoholics, with timing of separation highly dependent on alcoholic parent gender.

Micro-separation toward systems biology.

PubMed

Liu, Bi-Feng; Xu, Bo; Zhang, Guisen; Du, Wei; Luo, Qingming

2006-02-17

Current biology is experiencing transformation in logic or philosophy that forces us to reevaluate the concept of cell, tissue or entire organism as a collection of individual components. Systems biology that aims at understanding biological system at the systems level is an emerging research area, which involves interdisciplinary collaborations of life sciences, computational and mathematical sciences, systems engineering, and analytical technology, etc. For analytical chemistry, developing innovative methods to meet the requirement of systems biology represents new challenges as also opportunities and responsibility. In this review, systems biology-oriented micro-separation technologies are introduced for comprehensive profiling of genome, proteome and metabolome, characterization of biomolecules interaction and single cell analysis such as capillary electrophoresis, ultra-thin layer gel electrophoresis, micro-column liquid chromatography, and their multidimensional combinations, parallel integrations, microfabricated formats, and nano technology involvement. Future challenges and directions are also suggested.

Fluid-solid interaction: benchmarking of an external coupling of ANSYS with CFX for cardiovascular applications.

PubMed

Hose, D R; Lawford, P V; Narracott, A J; Penrose, J M T; Jones, I P

2003-01-01

Fluid-solid interaction is a primary feature of cardiovascular flows. There is increasing interest in the numerical solution of these systems as the extensive computational resource required for such studies becomes available. One form of coupling is an external weak coupling of separate solid and fluid mechanics codes. Information about the stress tensor and displacement vector at the wetted boundary is passed between the codes, and an iterative scheme is employed to move towards convergence of these parameters at each time step. This approach has the attraction that separate codes with the most extensive functionality for each of the separate phases can be selected, which might be important in the context of the complex rheology and contact mechanics that often feature in cardiovascular systems. Penrose and Staples describe a weak coupling of CFX for computational fluid mechanics to ANSYS for solid mechanics, based on a simple Jacobi iteration scheme. It is important to validate the coupled numerical solutions. An extensive analytical study of flow in elastic-walled tubes was carried out by Womersley in the late 1950s. This paper describes the performance of the coupling software for the straight elastic-walled tube, and compares the results with Womersley's analytical solutions. It also presents preliminary results demonstrating the application of the coupled software in the context of a stented vessel.

Multidimensional Riemann problem with self-similar internal structure - part III - a multidimensional analogue of the HLLI Riemann solver for conservative hyperbolic systems

NASA Astrophysics Data System (ADS)

Balsara, Dinshaw S.; Nkonga, Boniface

2017-10-01

Just as the quality of a one-dimensional approximate Riemann solver is improved by the inclusion of internal sub-structure, the quality of a multidimensional Riemann solver is also similarly improved. Such multidimensional Riemann problems arise when multiple states come together at the vertex of a mesh. The interaction of the resulting one-dimensional Riemann problems gives rise to a strongly-interacting state. We wish to endow this strongly-interacting state with physically-motivated sub-structure. The fastest way of endowing such sub-structure consists of making a multidimensional extension of the HLLI Riemann solver for hyperbolic conservation laws. Presenting such a multidimensional analogue of the HLLI Riemann solver with linear sub-structure for use on structured meshes is the goal of this work. The multidimensional MuSIC Riemann solver documented here is universal in the sense that it can be applied to any hyperbolic conservation law. The multidimensional Riemann solver is made to be consistent with constraints that emerge naturally from the Galerkin projection of the self-similar states within the wave model. When the full eigenstructure in both directions is used in the present Riemann solver, it becomes a complete Riemann solver in a multidimensional sense. I.e., all the intermediate waves are represented in the multidimensional wave model. The work also presents, for the very first time, an important analysis of the dissipation characteristics of multidimensional Riemann solvers. The present Riemann solver results in the most efficient implementation of a multidimensional Riemann solver with sub-structure. Because it preserves stationary linearly degenerate waves, it might also help with well-balancing. Implementation-related details are presented in pointwise fashion for the one-dimensional HLLI Riemann solver as well as the multidimensional MuSIC Riemann solver.

Coupled simulation of CFD-flight-mechanics with a two-species-gas-model for the hot rocket staging

NASA Astrophysics Data System (ADS)

Li, Yi; Reimann, Bodo; Eggers, Thino

2016-11-01

The hot rocket staging is to separate the lowest stage by directly ignite the continuing-stage-motor. During the hot staging, the rocket stages move in a harsh dynamic environment. In this work, the hot staging dynamics of a multistage rocket is studied using the coupled simulation of Computational Fluid Dynamics and Flight Mechanics. Plume modeling is crucial for a coupled simulation with high fidelity. A 2-species-gas model is proposed to simulate the flow system of the rocket during the staging: the free-stream is modeled as "cold air" and the exhausted plume from the continuing-stage-motor is modeled with an equivalent calorically-perfect-gas that approximates the properties of the plume at the nozzle exit. This gas model can well comprise between the computation accuracy and efficiency. In the coupled simulations, the Navier-Stokes equations are time-accurately solved in moving system, with which the Flight Mechanics equations can be fully coupled. The Chimera mesh technique is utilized to deal with the relative motions of the separated stages. A few representative staging cases with different initial flight conditions of the rocket are studied with the coupled simulation. The torque led by the plume-induced-flow-separation at the aft-wall of the continuing-stage is captured during the staging, which can assist the design of the controller of the rocket. With the increasing of the initial angle-of-attack of the rocket, the staging quality becomes evidently poorer, but the separated stages are generally stable when the initial angle-of-attack of the rocket is small.

Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).

PubMed

Lind, Emma E; Grahn, Mats

2011-05-01

Contamination can cause a rapid environmental change which may require populations to respond with evolutionary changes. To evaluate the effects of pulp mill effluents on population genetics, we sampled three-spined sticklebacks (Gasterosteus aculeatus) near four pulp mills and four adjacent reference sites and analyzed Amplified Fragment Length Polymorphism (AFLP) to compare genetic variability. A fine scale genetic structure was detected and samples from polluted sites separated from reference sites in multidimensional scaling plots (P<0.005, 1000 permutations) and locus-by-locus Analysis of Molecular Variance (AMOVA) further confirmed that habitats are significantly separated (F(ST)=0.021, P<0.01, 1023 permutations). The amount of genetic variation between populations did not differ between habitats, and populations from both habitats had similar levels of heterozygosity (polluted sites Nei's Hs=0.11, reference sites Nei's Hs=0.11). Still, pairwise F(ST): s between three, out of four, pairs of polluted-reference sites were significant. A F(ST)-outlier analysis showed that 21 (8.4%) loci were statistically different from a neutral distribution at the P<0.05 level and therefore indicated to be under divergent selection. When removing 13 F(ST)-outlier loci, significant at the P<0.01 level, differentiation between habitats disappeared in a multidimensional scaling plot. In conclusion, pulp mill effluence has acted as a selective agent on natural populations of G. aculeatus, causing a convergence in genotype composition change at multiple sites in an open environment. © The Author(s) 2011. This article is published with open access at Springerlink.com

Lateral separation of colloids or cells by dielectrophoresis augmented by AC electroosmosis.

PubMed

Zhou, Hao; White, Lee R; Tilton, Robert D

2005-05-01

Colloidal particles and biological cells are patterned and separated laterally adjacent to a micropatterned electrode array by applying AC electric fields that are principally oriented normally to the electrode array. This is demonstrated for yeast cells, red blood cells, and colloidal polystyrene particles of different sizes and zeta-potentials. The separation mechanism is observed experimentally to depend on the applied field frequency and voltage. At high frequencies, particles position themselves in a manner that is consistent with dielectrophoresis, while at low frequencies, the positioning is explained in terms of a strong coupling between gravity, the vertical component of the dielectrophoretic force, and the Stokes drag on particles induced by AC electroosmotic flow. Compared to high frequency dielectrophoretic separations, the low frequency separations are faster and require lower applied voltages. Furthermore, the AC electroosmosis coupling with dielectrophoresis may enable cell separations that are not feasible based on dielectrophoresis alone.

Using Multidimensional Grief Theory to Explore Effects of Deployment, Reintegration, and Death on Military Youth and Families

PubMed Central

Kaplow, Julie B.; Layne, Christopher M.; Saltzman, William R.; Cozza, Stephen J.; Pynoos, Robert S.

2015-01-01

To date, the U.S. military has made major strides in acknowledging and therapeutically addressing trauma and Posttraumatic Stress Disorder (PTSD) in service members and their families. However, given the nature of warfare and high rates of losses sustained by both military members (e.g., deaths of fellow unit members) and military families (e.g., loss of a young parent who served in the military), as well as the ongoing threat of loss that military families face during deployment, we propose that a similar focus on grief is also needed to properly understand and address many of the challenges encountered by bereaved service members, spouses, and children. In this article, we describe a newly developed theory of grief (Multidimensional Grief Theory) and apply it to the task of exploring major features of military-related experiences during the phases of deployment, reintegration, and the aftermath of combat death—especially as they impact children. We also describe implications for designing preventive interventions during each phase and conclude with recommended avenues for future research. Primary aims are to illustrate: (1) the indispensable role of theory in guiding efforts to describe, explain, predict, prevent, and treat maladaptive grief in military service members, children, and families; (2) the relevance of multidimensional grief theory for addressing both losses due to physical death as well as losses brought about by extended physical separations to which military children and families are exposed during and after deployment; and (3) a focus on military-related grief as a much-needed complement to an already-established focus on military-related PTSD. PMID:23760905

Using multidimensional grief theory to explore the effects of deployment, reintegration, and death on military youth and families.

PubMed

Kaplow, Julie B; Layne, Christopher M; Saltzman, William R; Cozza, Stephen J; Pynoos, Robert S

2013-09-01

To date, the US military has made major strides in acknowledging and therapeutically addressing trauma and post-traumatic stress disorder (PTSD) in service members and their families. However, given the nature of warfare and high rates of losses sustained by both military members (e.g., deaths of fellow unit members) and military families (e.g., loss of a young parent who served in the military), as well as the ongoing threat of loss that military families face during deployment, we propose that a similar focus on grief is also needed to properly understand and address many of the challenges encountered by bereaved service members, spouses, and children. In this article, we describe a newly developed theory of grief (multidimensional grief theory) and apply it to the task of exploring major features of military-related experiences during the phases of deployment, reintegration, and the aftermath of combat death--especially as they impact children. We also describe implications for designing preventive interventions during each phase and conclude with recommended avenues for future research. Primary aims are to illustrate: (1) the indispensable role of theory in guiding efforts to describe, explain, predict, prevent, and treat maladaptive grief in military service members, children, and families; (2) the relevance of multidimensional grief theory for addressing both losses due to physical death as well as losses brought about by extended physical separations to which military children and families are exposed during and after deployment; and (3) a focus on military-related grief as a much-needed complement to an already-established focus on military-related PTSD.

The Nature of Science Instrument-Elementary (NOSI-E): the end of the road?

PubMed

Peoples, Shelagh M; O'Dwyer, Laura M

2014-01-01

This research continues prior work published in this journal (Peoples, O'Dwyer, Shields and Wang, 2013). The first paper described the scale development, psychometric analyses and part-validation of a theoretically-grounded Rasch-based instrument, the Nature of Science Instrument-Elementary (NOSI-E). The NOSI-E was designed to measure elementary students' understanding of the Nature of Science (NOS). In the first paper, evidence was provided for three of the six validity aspects (content, substantive and generalizability) needed to support the construct validity of the NOSI-E. The research described in this paper examines two additional validity aspects (structural and external). The purpose of this study was to determine which of three competing internal models provides reliable, interpretable, and responsive measures of students' understanding of NOS. One postulate is that the NOS construct is unidimensional;. alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. The vast body of evidence supported the claim that the NOS construct is multidimensional. Measures from the multidimensional model were positively related to student science achievement and students' perceptions of their classroom environment; this provided supporting evidence for the external validity aspect of the NOS construct. As US science education moves toward students learning science through engaging in authentic scientific practices and building learning progressions (NRC, 2012), it will be important to assess whether this new approach to teaching science is effective, and the NOSI-E may be used as a measure of the impact of this reform.

Multidimensional spectrometer

DOEpatents

Zanni, Martin Thomas; Damrauer, Niels H.

2010-07-20

A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schluck, F.; Lehmann, G.; Müller, C.

Short laser pulse amplification via stimulated Brillouin backscattering in plasma is considered. Previous work distinguishes between the weakly and strongly coupled regime and treats them separately. It is shown here that such a separation is not generally applicable because strong and weak coupling interaction regimes are entwined with each other. An initially weakly coupled amplification scenario may dynamically transform into strong coupling. This happens when the local seed amplitude grows and thus triggers the strongly driven plasma response. On the other hand, when in a strong coupling scenario, the pump pulse gets depleted, and its amplitude might drop below themore » strong coupling threshold. This may cause significant changes in the final seed pulse shape. Furthermore, experimentally used pump pulses are typically Gaussian-shaped. The intensity threshold for strong coupling may only be exceeded around the maximum and not in the wings of the pulse. Also here, a description valid in both strong and weak coupling regimes is required. We propose such a unified treatment which allows us, in particular, to study the dynamic transition between weak and strong coupling. Consequences for the pulse forms of the amplified seed are discussed.« less

Hydrophilic Strong Anion Exchange (hSAX) Chromatography for Highly Orthogonal Peptide Separation of Complex Proteomes

PubMed Central

2013-01-01

Due to its compatibility and orthogonality to reversed phase (RP) liquid chromatography (LC) separation, ion exchange chromatography, and mainly strong cation exchange (SCX), has often been the first choice in multidimensional LC experiments in proteomics. Here, we have tested the ability of three strong anion exchanger (SAX) columns differing in their hydrophobicity to fractionate RAW264.7 macrophage cell lysate. IonPac AS24, a strong anion exchange material with ultralow hydrophobicity, demonstrated to be superior to other materials by fractionation and separation of tryptic peptides from both a mixture of 6 proteins as well as mouse cell lysate. The chromatography displayed very high orthogonality and high robustness depending on the hydrophilicity of column chemistry, which we termed hydrophilic strong anion exchange (hSAX). Mass spectrometry analysis of 34 SAX fractions from RAW264.7 macrophage cell lysate digest resulted in an identification of 9469 unique proteins and 126318 distinct peptides in one week of instrument time. Moreover, when compared to an optimized high pH/low pH RP separation approach, the method presented here raised the identification of proteins and peptides by 10 and 28%, respectively. This novel hSAX approach provides robust, reproducible, and highly orthogonal separation of complex protein digest samples for deep coverage proteome analysis. PMID:23294059

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddi, Balakrishna; Panisko, Ellen; Albrecht, Karl

Two-dimensional gas chromatography coupled with time of flight mass spectrometry is a powerful tool for identifying and quantifying components in complex mixtures. It has been used to analyze gasoline, jet fuel, diesel, bio-diesel and organic fraction of bio-crude/bio-oil. In these experiments, the first dimension of separation was non-polar, followed by a polar separation. Aqueous fractions of bio-crude and other aqueous samples have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessary prior to analysis. In this study, aqueous fraction obtained from hydrothermal liquefaction of algae was characterized by two-dimensionalmore » gas chromatography coupled with time of flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column combination. Results from qualitative characterization aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time of flight mass spectrometry are highlighted.« less

Plasmon Ruler with Ångstrom Length Resolution

PubMed Central

Hill, Ryan T.; Mock, Jack J.; Hucknall, Angus; Wolter, Scott D.; Jokerst, Nan M.; Smith, David R.; Chilkoti, Ashutosh

2012-01-01

We demonstrate a plasmon nanoruler using a coupled film-nanoparticle (film-NP) format that is well suited for investigating the sensitivity extremes of plasmonic coupling. Because it is relatively straightforward to functionalize bulk, surface plasmon supporting films such as gold, we are able to precisely control plasmonic gap dimensions by creating ultra-thin molecular spacer layers on the gold films, on top of which we immobilize plasmon resonant nanoparticles (NPs). Each immobilized NP becomes coupled to the underlying film and functions as a plasmon nanoruler, exhibiting a distance-dependent resonance red-shift in its peak plasmon wavelength as it approaches the film. Due to the uniformity of response from the film-NPs to separation distance, we are able to use extinction and scattering measurements from ensembles of film-NPs to characterize the coupling effect over a series of very short separation distances – ranging from 5 – 20 Å – and combine these measurements with similar data from larger separation distances extending out to 27 nm. We find that the film-NP plasmon nanoruler is extremely sensitive at very short film-NP separation distances, yielding spectral shifts as large as 5 nm for every 1 Å change in separation distance. The film-NP coupling at extremely small spacings is so uniform and reliable that we are able to usefully probe gap dimensions where the classical Drude model of the conducting electrons in the metals is no longer descriptive; for gap sizes smaller than a few nanometers, either quantum or semi-classical models of the carrier response must be employed to predict the observed wavelength shifts. We find that, despite the limitations, large field enhancements and extreme sensitivity persist down to even the smallest gap sizes. PMID:22966857

Plasmon ruler with angstrom length resolution.

PubMed

Hill, Ryan T; Mock, Jack J; Hucknall, Angus; Wolter, Scott D; Jokerst, Nan M; Smith, David R; Chilkoti, Ashutosh

2012-10-23

We demonstrate a plasmon nanoruler using a coupled film nanoparticle (film-NP) format that is well-suited for investigating the sensitivity extremes of plasmonic coupling. Because it is relatively straightforward to functionalize bulk surface plasmon supporting films, such as gold, we are able to precisely control plasmonic gap dimensions by creating ultrathin molecular spacer layers on the gold films, on top of which we immobilize plasmon resonant nanoparticles (NPs). Each immobilized NP becomes coupled to the underlying film and functions as a plasmon nanoruler, exhibiting a distance-dependent resonance red shift in its peak plasmon wavelength as it approaches the film. Due to the uniformity of response from the film-NPs to separation distance, we are able to use extinction and scattering measurements from ensembles of film-NPs to characterize the coupling effect over a series of very short separation distances-ranging from 5 to 20 Å-and combine these measurements with similar data from larger separation distances extending out to 27 nm. We find that the film-NP plasmon nanoruler is extremely sensitive at very short film-NP separation distances, yielding spectral shifts as large as 5 nm for every 1 Å change in separation distance. The film-NP coupling at extremely small spacings is so uniform and reliable that we are able to usefully probe gap dimensions where the classical Drude model of the conducting electrons in the metals is no longer descriptive; for gap sizes smaller than a few nanometers, either quantum or semiclassical models of the carrier response must be employed to predict the observed wavelength shifts. We find that, despite the limitations, large field enhancements and extreme sensitivity persist down to even the smallest gap sizes.

Control of multidimensional systems on complex network

PubMed Central

Bagnoli, Franco; Battistelli, Giorgio; Chisci, Luigi; Fanelli, Duccio

2017-01-01

Multidimensional systems coupled via complex networks are widespread in nature and thus frequently invoked for a large plethora of interesting applications. From ecology to physics, individual entities in mutual interactions are grouped in families, homogeneous in kind. These latter interact selectively, through a sequence of self-consistently regulated steps, whose deeply rooted architecture is stored in the assigned matrix of connections. The asymptotic equilibrium eventually attained by the system, and its associated stability, can be assessed by employing standard nonlinear dynamics tools. For many practical applications, it is however important to externally drive the system towards a desired equilibrium, which is resilient, hence stable, to external perturbations. To this end we here consider a system made up of N interacting populations which evolve according to general rate equations, bearing attributes of universality. One species is added to the pool of interacting families and used as a dynamical controller to induce novel stable equilibria. Use can be made of the root locus method to shape the needed control, in terms of intrinsic reactivity and adopted protocol of injection. The proposed method is tested on both synthetic and real data, thus enabling to demonstrate its robustness and versatility. PMID:28892493

A multi scale multi-dimensional thermo electrochemical modelling of high capacity lithium-ion cells

NASA Astrophysics Data System (ADS)

Tourani, Abbas; White, Peter; Ivey, Paul

2014-06-01

Lithium iron phosphate (LFP) and lithium manganese oxide (LMO) are competitive and complementary to each other as cathode materials for lithium-ion batteries, especially for use in electric vehicles. A multi scale multi-dimensional physic-based model is proposed in this paper to study the thermal behaviour of the two lithium-ion chemistries. The model consists of two sub models, a one dimensional (1D) electrochemical sub model and a two dimensional (2D) thermo-electric sub model, which are coupled and solved concurrently. The 1D model predicts the heat generation rate (Qh) and voltage (V) of the battery cell through different load cycles. The 2D model of the battery cell accounts for temperature distribution and current distribution across the surface of the battery cell. The two cells are examined experimentally through 90 h load cycles including high/low charge/discharge rates. The experimental results are compared with the model results and they are in good agreement. The presented results in this paper verify the cells temperature behaviour at different operating conditions which will lead to the design of a cost effective thermal management system for the battery pack.

A novel second-order standard addition analytical method based on data processing with multidimensional partial least-squares and residual bilinearization.

PubMed

Lozano, Valeria A; Ibañez, Gabriela A; Olivieri, Alejandro C

2009-10-05

In the presence of analyte-background interactions and a significant background signal, both second-order multivariate calibration and standard addition are required for successful analyte quantitation achieving the second-order advantage. This report discusses a modified second-order standard addition method, in which the test data matrix is subtracted from the standard addition matrices, and quantitation proceeds via the classical external calibration procedure. It is shown that this novel data processing method allows one to apply not only parallel factor analysis (PARAFAC) and multivariate curve resolution-alternating least-squares (MCR-ALS), but also the recently introduced and more flexible partial least-squares (PLS) models coupled to residual bilinearization (RBL). In particular, the multidimensional variant N-PLS/RBL is shown to produce the best analytical results. The comparison is carried out with the aid of a set of simulated data, as well as two experimental data sets: one aimed at the determination of salicylate in human serum in the presence of naproxen as an additional interferent, and the second one devoted to the analysis of danofloxacin in human serum in the presence of salicylate.

Network structure of multivariate time series.

PubMed

Lacasa, Lucas; Nicosia, Vincenzo; Latora, Vito

2015-10-21

Our understanding of a variety of phenomena in physics, biology and economics crucially depends on the analysis of multivariate time series. While a wide range tools and techniques for time series analysis already exist, the increasing availability of massive data structures calls for new approaches for multidimensional signal processing. We present here a non-parametric method to analyse multivariate time series, based on the mapping of a multidimensional time series into a multilayer network, which allows to extract information on a high dimensional dynamical system through the analysis of the structure of the associated multiplex network. The method is simple to implement, general, scalable, does not require ad hoc phase space partitioning, and is thus suitable for the analysis of large, heterogeneous and non-stationary time series. We show that simple structural descriptors of the associated multiplex networks allow to extract and quantify nontrivial properties of coupled chaotic maps, including the transition between different dynamical phases and the onset of various types of synchronization. As a concrete example we then study financial time series, showing that a multiplex network analysis can efficiently discriminate crises from periods of financial stability, where standard methods based on time-series symbolization often fail.

Tunneling splitting in double-proton transfer: direct diagonalization results for porphycene.

PubMed

Smedarchina, Zorka; Siebrand, Willem; Fernández-Ramos, Antonio

2014-11-07

Zero-point and excited level splittings due to double-proton tunneling are calculated for porphycene and the results are compared with experiment. The calculation makes use of a multidimensional imaginary-mode Hamiltonian, diagonalized directly by an effective reduction of its dimensionality. Porphycene has a complex potential energy surface with nine stationary configurations that allow a variety of tunneling paths, many of which include classically accessible regions. A symmetry-based approach is used to show that the zero-point level, although located above the cis minimum, corresponds to concerted tunneling along a direct trans - trans path; a corresponding cis - cis path is predicted at higher energy. This supports the conclusion of a previous paper [Z. Smedarchina, W. Siebrand, and A. Fernández-Ramos, J. Chem. Phys. 127, 174513 (2007)] based on the instanton approach to a model Hamiltonian of correlated double-proton transfer. A multidimensional tunneling Hamiltonian is then generated, based on a double-minimum potential along the coordinate of concerted proton motion, which is newly evaluated at the RI-CC2/cc-pVTZ level of theory. To make it suitable for diagonalization, its dimensionality is reduced by treating fast weakly coupled modes in the adiabatic approximation. This results in a coordinate-dependent mass of tunneling, which is included in a unique Hermitian form into the kinetic energy operator. The reduced Hamiltonian contains three symmetric and one antisymmetric mode coupled to the tunneling mode and is diagonalized by a modified Jacobi-Davidson algorithm implemented in the Jadamilu software for sparse matrices. The results are in satisfactory agreement with the observed splitting of the zero-point level and several vibrational fundamentals after a partial reassignment, imposed by recently derived selection rules. They also agree well with instanton calculations based on the same Hamiltonian.

On Green's function retrieval by iterative substitution of the coupled Marchenko equations

NASA Astrophysics Data System (ADS)

van der Neut, Joost; Vasconcelos, Ivan; Wapenaar, Kees

2015-11-01

Iterative substitution of the coupled Marchenko equations is a novel methodology to retrieve the Green's functions from a source or receiver array at an acquisition surface to an arbitrary location in an acoustic medium. The methodology requires as input the single-sided reflection response at the acquisition surface and an initial focusing function, being the time-reversed direct wavefield from the acquisition surface to a specified location in the subsurface. We express the iterative scheme that is applied by this methodology explicitly as the successive actions of various linear operators, acting on an initial focusing function. These operators involve multidimensional crosscorrelations with the reflection data and truncations in time. We offer physical interpretations of the multidimensional crosscorrelations by subtracting traveltimes along common ray paths at the stationary points of the underlying integrals. This provides a clear understanding of how individual events are retrieved by the scheme. Our interpretation also exposes some of the scheme's limitations in terms of what can be retrieved in case of a finite recording aperture. Green's function retrieval is only successful if the relevant stationary points are sampled. As a consequence, internal multiples can only be retrieved at a subsurface location with a particular ray parameter if this location is illuminated by the direct wavefield with this specific ray parameter. Several assumptions are required to solve the Marchenko equations. We show that these assumptions are not always satisfied in arbitrary heterogeneous media, which can result in incomplete Green's function retrieval and the emergence of artefacts. Despite these limitations, accurate Green's functions can often be retrieved by the iterative scheme, which is highly relevant for seismic imaging and inversion of internal multiple reflections.

Design of a new separable rotary transformer

NASA Astrophysics Data System (ADS)

Gong, X. F.; Zhang, L.; Feng, E. J.

2017-09-01

A new-type separable rotary transformer which can be used in rotary steerable drilling is designed to deliver power efficiently from a stationary primary source to a rotary secondary load over a relatively large air gap via magnetic coupling. In this paper, E-type magnetic cores are reasonably distributed so that rotation of the rotary secondary has the least influence on reluctance of magnetic coupling. The influence of different winding layouts and connection modes on self-inductance and coupling coefficient is studied. By analysing the influence of the different geometrical shapes of cores on magnetic path, a design principle is proposed.

Surface-enhanced Raman spectroscopy on coupled two-layer nanorings

NASA Astrophysics Data System (ADS)

Hou, Yumin; Xu, Jun; Wang, Pengwei; Yu, Dapeng

2010-05-01

A reproducible quasi-three-dimensional structure, composed of top and bottom concentric nanorings with same periodicity but different widths and no overlapping at the perpendicular direction, is built up by a separation-layer method, which results in huge enhancement of surface-enhanced Raman spectroscopy (SERS) due to the coupling of plasmons. Simulations show plasmonic focusing with "hot arcs" of electromagnetic enhancement meeting the need of quantitative SERS with extremely high sensitivities. In addition, the separation-layer method opens a simple and effective way to adjust the coupling of plasmons among nanostructures which is essential for the fabrication of SERS-based sensors.

Evanescent wave coupling in terahertz waveguide arrays.

PubMed

Reichel, K S; Sakoda, N; Mendis, R; Mittleman, D M

2013-07-15

We study energy transfer among an array of identical finite-width parallel-plate waveguides in close proximity, via evanescent wave coupling of broadband terahertz waves. We observe stronger coupling with larger plate separations and longer propagation paths. This work establishes a platform to investigate new opportunities for THz components and devices based on evanescent wave coupling.

Coupled dual loop absorption heat pump

DOEpatents

Sarkisian, Paul H.; Reimann, Robert C.; Biermann, Wendell J.

1985-01-01

A coupled dual loop absorption system which utilizes two separate complete loops. Each individual loop operates at three temperatures and two pressures. This low temperature loop absorber and condenser are thermally coupled to the high temperature loop evaporator, and the high temperature loop condenser and absorber are thermally coupled to the low temperature generator.

Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

PubMed Central

Heshka, Nicole E.; Hager, Darcy B.

2015-01-01

A method for the analysis of dissolved hydrogen sulfide in crude oil samples is demonstrated using gas chromatography. In order to effectively eliminate interferences, a two dimensional column configuration is used, with a Deans switch employed to transfer hydrogen sulfide from the first to the second column (heart-cutting). Liquid crude samples are first separated on a dimethylpolysiloxane column, and light gases are heart-cut and further separated on a bonded porous layer open tubular (PLOT) column that is able to separate hydrogen sulfide from other light sulfur species. Hydrogen sulfide is then detected with a sulfur chemiluminescence detector, adding an additional layer of selectivity. Following separation and detection of hydrogen sulfide, the system is backflushed to remove the high-boiling hydrocarbons present in the crude samples and to preserve chromatographic integrity. Dissolved hydrogen sulfide has been quantified in liquid samples from 1.1 to 500 ppm, demonstrating wide applicability to a range of samples. The method has also been successfully applied for the analysis of gas samples from crude oil headspace and process gas bags, with measurement from 0.7 to 9,700 ppm hydrogen sulfide. PMID:26709594

Selective Detection of Peptide-Oligonucleotide Heteroconjugates Utilizing Capillary HPLC-ICPMS

NASA Astrophysics Data System (ADS)

Catron, Brittany; Caruso, Joseph A.; Limbach, Patrick A.

2012-06-01

A method for the selective detection and quantification of peptide:oligonucleotide heteroconjugates, such as those generated by protein:nucleic acid cross-links, using capillary reversed-phase high performance liquid chromatography (cap-RPHPLC) coupled with inductively coupled plasma mass spectrometry detection (ICPMS) is described. The selective detection of phosphorus as 31P+, the only natural isotope, in peptide-oligonucleotide heteroconjugates is enabled by the elemental detection capabilities of the ICPMS. Mobile phase conditions that allow separation of heteroconjugates while maintaining ICPMS compatibility were investigated. We found that trifluoroacetic acid (TFA) mobile phases, used in conventional peptide separations, and hexafluoroisopropanol/triethylamine (HFIP/TEA) mobile phases, used in conventional oligonucleotide separations, both are compatible with ICPMS and enable heteroconjugate separation. The TFA-based separations yielded limits of detection (LOD) of ~40 ppb phosphorus, which is nearly seven times lower than the LOD for HFIP/TEA-based separations. Using the TFA mobile phase, 1-2 pmol of a model heteroconjugate were routinely separated and detected by this optimized capLC-ICPMS method.

A structural examination and collision cross section database for over 500 metabolites and xenobiotics using drift tube ion mobility spectrometry† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc03464d

PubMed Central

Zheng, Xueyun; Aly, Noor A.; Zhou, Yuxuan; Dupuis, Kevin T.; Bilbao, Aivett; Paurus, Vanessa L.; Orton, Daniel J.; Wilson, Ryan; Payne, Samuel H.; Smith, Richard D.

2017-01-01

The confident identification of metabolites and xenobiotics in biological and environmental studies is an analytical challenge due to their immense dynamic range, vast chemical space and structural diversity. Ion mobility spectrometry (IMS) is widely used for small molecule analyses since it can separate isomeric species and be easily coupled with front end separations and mass spectrometry for multidimensional characterizations. However, to date IMS metabolomic and exposomic studies have been limited by an inadequate number of accurate collision cross section (CCS) values for small molecules, causing features to be detected but not confidently identified. In this work, we utilized drift tube IMS (DTIMS) to directly measure CCS values for over 500 small molecules including primary metabolites, secondary metabolites and xenobiotics. Since DTIMS measurements do not need calibrant ions or calibration like some other IMS techniques, they avoid calibration errors which can cause problems in distinguishing structurally similar molecules. All measurements were performed in triplicate in both positive and negative polarities with nitrogen gas and seven different electric fields, so that relative standard deviations (RSD) could be assessed for each molecule and structural differences studied. The primary metabolites analyzed to date have come from key metabolism pathways such as glycolysis, the pentose phosphate pathway and the tricarboxylic acid cycle, while the secondary metabolites consisted of classes such as terpenes and flavonoids, and the xenobiotics represented a range of molecules from antibiotics to polycyclic aromatic hydrocarbons. Different CCS trends were observed for several of the diverse small molecule classes and when urine features were matched to the database, the addition of the IMS dimension greatly reduced the possible number of candidate molecules. This CCS database and structural information are freely available for download at http://panomics.pnnl.gov/metabolites/ with new molecules being added frequently. PMID:29568436

Modeling RP-1 fuel advanced distillation data using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry and partial least squares analysis.

PubMed

Kehimkar, Benjamin; Parsons, Brendon A; Hoggard, Jamin C; Billingsley, Matthew C; Bruno, Thomas J; Synovec, Robert E

2015-01-01

Recent efforts in predicting rocket propulsion (RP-1) fuel performance through modeling put greater emphasis on obtaining detailed and accurate fuel properties, as well as elucidating the relationships between fuel compositions and their properties. Herein, we study multidimensional chromatographic data obtained by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC × GC-TOFMS) to analyze RP-1 fuels. For GC × GC separations, RTX-Wax (polar stationary phase) and RTX-1 (non-polar stationary phase) columns were implemented for the primary and secondary dimensions, respectively, to separate the chemical compound classes (alkanes, cycloalkanes, aromatics, etc.), providing a significant level of chemical compositional information. The GC × GC-TOFMS data were analyzed using partial least squares regression (PLS) chemometric analysis to model and predict advanced distillation curve (ADC) data for ten RP-1 fuels that were previously analyzed using the ADC method. The PLS modeling provides insight into the chemical species that impact the ADC data. The PLS modeling correlates compositional information found in the GC × GC-TOFMS chromatograms of each RP-1 fuel, and their respective ADC, and allows prediction of the ADC for each RP-1 fuel with good precision and accuracy. The root-mean-square error of calibration (RMSEC) ranged from 0.1 to 0.5 °C, and was typically below ∼0.2 °C, for the PLS calibration of the ADC modeling with GC × GC-TOFMS data, indicating a good fit of the model to the calibration data. Likewise, the predictive power of the overall method via PLS modeling was assessed using leave-one-out cross-validation (LOOCV) yielding root-mean-square error of cross-validation (RMSECV) ranging from 1.4 to 2.6 °C, and was typically below ∼2.0 °C, at each % distilled measurement point during the ADC analysis.

“So We Adapt Step by Step”: Acculturation Experiences Affecting Diabetes Management and Perceived Health for Chinese American Immigrants

PubMed Central

Chun, Kevin M.; Chesla, Catherine A.; Kwan, Christine M.L.

2011-01-01

This study examines how acculturation affects type 2 diabetes management and perceived health for Chinese American immigrants in the U.S. Acculturation experiences or cultural adaptation experiences affecting diabetes management and health were solicited from an informant group of immigrant patients and their spouses (N=40) during group, couple and individual interviews conducted in 2005 to 2008. A separate respondent group of immigrant patients and their spouses (N=19) meeting inclusion criteria reviewed and confirmed themes generated by the informant group. Using interpretive phenomenology, three key themes in patients’ and spouses’ acculturation experiences were identified: a) utilizing health care, b) maintaining family relations and roles, and c) establishing community ties and groundedness in the U.S. Acculturation experiences reflecting these themes were broad in scope and not fully captured by current self-report and proxy acculturation measures. In the current study, shifting family roles and evaluations of diabetes care and physical environment in the U.S. significantly affected diabetes management and health, yet are overlooked in acculturation and health investigations. Furthermore, the salience and impact of specific acculturation experiences respective to diabetes management and perceived health varied across participants due to individual, family, developmental, and environmental factors. In regards to salience, maintaining filial and interdependent family relations in the U.S. was of particular concern for older participants and coping with inadequate health insurance in the U.S. was especially distressing for self-described lower-middle to middle-class participants. In terms of impact, family separation and relocating to ethnically similar neighborhoods in the U.S. differentially affected diabetes management and health due to participants’ varied family relations and pre-migration family support levels and diverse cultural and linguistic backgrounds, respectively. Implications for expanding current conceptualizations and measures of acculturation to better comprehend its dynamic and multidimensional properties and complex effects on health are discussed. Additionally, implications for developing culturally-appropriate diabetes management recommendations for Chinese immigrants and their families are outlined. PMID:21147509

Chiral stationary phase optimized selectivity liquid chromatography: A strategy for the separation of chiral isomers.

PubMed

Hegade, Ravindra Suryakant; De Beer, Maarten; Lynen, Frederic

2017-09-15

Chiral Stationary-Phase Optimized Selectivity Liquid Chromatography (SOSLC) is proposed as a tool to optimally separate mixtures of enantiomers on a set of commercially available coupled chiral columns. This approach allows for the prediction of the separation profiles on any possible combination of the chiral stationary phases based on a limited number of preliminary analyses, followed by automated selection of the optimal column combination. Both the isocratic and gradient SOSLC approach were implemented for prediction of the retention times for a mixture of 4 chiral pairs on all possible combinations of the 5 commercial chiral columns. Predictions in isocratic and gradient mode were performed with a commercially available and with an in-house developed Microsoft visual basic algorithm, respectively. Optimal predictions in the isocratic mode required the coupling of 4 columns whereby relative deviations between the predicted and experimental retention times ranged between 2 and 7%. Gradient predictions led to the coupling of 3 chiral columns allowing baseline separation of all solutes, whereby differences between predictions and experiments ranged between 0 and 12%. The methodology is a novel tool allowing optimizing the separation of mixtures of optical isomers. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct coupling of polymer-based microchip electrophoresis to online MALDI-MS using a rotating ball inlet.

PubMed

Musyimi, Harrison K; Guy, Jason; Narcisse, Damien A; Soper, Steven A; Murray, Kermit K

2005-12-01

We report on the coupling of a polymer-based microfluidic chip to a MALDI-TOF MS using a rotating ball interface. The microfluidic chips were fabricated by micromilling a mold insert into a brass plate, which was then used for replicating polymer microparts via hot embossing. Assembly of the chip was accomplished by thermally annealing a cover slip to the embossed substrate to enclose the channels. The linear separation channel was 50 microm wide, 100 microm deep, and possessed an 8 cm effective length separation channel with a double-T injector (V(inj) = 10 nL). The exit of the separation channel was machined to allow direct contact deposition of effluent onto a specially constructed rotating ball inlet to the mass spectrometer. Matrix addition was accomplished in-line on the surface of the ball. The coupling utilized the ball as the cathode transfer electrode to transport sample into the vacuum for desorption with a 355 nm Nd:YAG laser and analyzed on a TOF mass spectrometer. The ball was cleaned online after every rotation. The ability to couple poly(methylmethacrylate) microchip electrophoresis devices for the separation of peptides and peptide fragments produced from a protein digest with subsequent online MALDI MS detection was demonstrated.

Combining gas-phase electrophoretic mobility molecular analysis (GEMMA), light scattering, field flow fractionation and cryo electron microscopy in a multidimensional approach to characterize liposomal carrier vesicles.

PubMed

Urey, Carlos; Weiss, Victor U; Gondikas, Andreas; von der Kammer, Frank; Hofmann, Thilo; Marchetti-Deschmann, Martina; Allmaier, Günter; Marko-Varga, György; Andersson, Roland

2016-11-20

For drug delivery, characterization of liposomes regarding size, particle number concentrations, occurrence of low-sized liposome artefacts and drug encapsulation are of importance to understand their pharmacodynamic properties. In our study, we aimed to demonstrate the applicability of nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analyser (nES GEMMA) as a suitable technique for analyzing these parameters. We measured number-based particle concentrations, identified differences in size between nominally identical liposomal samples, and detected the presence of low-diameter material which yielded bimodal particle size distributions. Subsequently, we compared these findings to dynamic light scattering (DLS) data and results from light scattering experiments coupled to Asymmetric Flow-Field Flow Fractionation (AF4), the latter improving the detectability of smaller particles in polydisperse samples due to a size separation step prior detection. However, the bimodal size distribution could not be detected due to method inherent limitations. In contrast, cryo transmission electron microscopy corroborated nES GEMMA results. Hence, gas-phase electrophoresis proved to be a versatile tool for liposome characterization as it could analyze both vesicle size and size distribution. Finally, a correlation of nES GEMMA results with cell viability experiments was carried out to demonstrate the importance of liposome batch-to-batch control as low-sized sample components possibly impact cell viability. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Towards sub-optimal stochastic control of partially observable stochastic systems

NASA Technical Reports Server (NTRS)

Ruzicka, G. J.

1980-01-01

A class of multidimensional stochastic control problems with noisy data and bounded controls encountered in aerospace design is examined. The emphasis is on suboptimal design, the optimality being taken in quadratic mean sense. To that effect the problem is viewed as a stochastic version of the Lurie problem known from nonlinear control theory. The main result is a separation theorem (involving a nonlinear Kalman-like filter) suitable for Lurie-type approximations. The theorem allows for discontinuous characteristics. As a byproduct the existence of strong solutions to a class of non-Lipschitzian stochastic differential equations in dimensions is proven.

Particle identification with neural networks using a rotational invariant moment representation

NASA Astrophysics Data System (ADS)

Sinkus, R.; Voss, T.

1997-02-01

A feed-forward neural network is used to identify electromagnetic particles based upon their showering properties within a segmented calorimeter. The novel feature is the expansion of the energy distribution in terms of moments of the so-called Zernike functions which are invariant under rotation. The multidimensional input distribution for the neural network is transformed via a principle component analysis and rescaled by its respective variances to ensure input values of the order of one. This results is a better performance in identifying and separating electromagnetic from hadronic particles, especially at low energies.

Numeric invariants from multidimensional persistence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skryzalin, Jacek; Carlsson, Gunnar

2017-05-19

In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be usedmore » to study data.« less

Gradient-based multiconfiguration Shepard interpolation for generating potential energy surfaces for polyatomic reactions.

PubMed

Tishchenko, Oksana; Truhlar, Donald G

2010-02-28

This paper describes and illustrates a way to construct multidimensional representations of reactive potential energy surfaces (PESs) by a multiconfiguration Shepard interpolation (MCSI) method based only on gradient information, that is, without using any Hessian information from electronic structure calculations. MCSI, which is called multiconfiguration molecular mechanics (MCMM) in previous articles, is a semiautomated method designed for constructing full-dimensional PESs for subsequent dynamics calculations (classical trajectories, full quantum dynamics, or variational transition state theory with multidimensional tunneling). The MCSI method is based on Shepard interpolation of Taylor series expansions of the coupling term of a 2 x 2 electronically diabatic Hamiltonian matrix with the diagonal elements representing nonreactive analytical PESs for reactants and products. In contrast to the previously developed method, these expansions are truncated in the present version at the first order, and, therefore, no input of electronic structure Hessians is required. The accuracy of the interpolated energies is evaluated for two test reactions, namely, the reaction OH+H(2)-->H(2)O+H and the hydrogen atom abstraction from a model of alpha-tocopherol by methyl radical. The latter reaction involves 38 atoms and a 108-dimensional PES. The mean unsigned errors averaged over a wide range of representative nuclear configurations (corresponding to an energy range of 19.5 kcal/mol in the former case and 32 kcal/mol in the latter) are found to be within 1 kcal/mol for both reactions, based on 13 gradients in one case and 11 in the other. The gradient-based MCMM method can be applied for efficient representations of multidimensional PESs in cases where analytical electronic structure Hessians are too expensive or unavailable, and it provides new opportunities to employ high-level electronic structure calculations for dynamics at an affordable cost.

Comparative exploration of multidimensional flow cytometry software: a model approach evaluating T cell polyfunctional behavior.

PubMed

Spear, Timothy T; Nishimura, Michael I; Simms, Patricia E

2017-08-01

Advancement in flow cytometry reagents and instrumentation has allowed for simultaneous analysis of large numbers of lineage/functional immune cell markers. Highly complex datasets generated by polychromatic flow cytometry require proper analytical software to answer investigators' questions. A problem among many investigators and flow cytometry Shared Resource Laboratories (SRLs), including our own, is a lack of access to a flow cytometry-knowledgeable bioinformatics team, making it difficult to learn and choose appropriate analysis tool(s). Here, we comparatively assess various multidimensional flow cytometry software packages for their ability to answer a specific biologic question and provide graphical representation output suitable for publication, as well as their ease of use and cost. We assessed polyfunctional potential of TCR-transduced T cells, serving as a model evaluation, using multidimensional flow cytometry to analyze 6 intracellular cytokines and degranulation on a per-cell basis. Analysis of 7 parameters resulted in 128 possible combinations of positivity/negativity, far too complex for basic flow cytometry software to analyze fully. Various software packages were used, analysis methods used in each described, and representative output displayed. Of the tools investigated, automated classification of cellular expression by nonlinear stochastic embedding (ACCENSE) and coupled analysis in Pestle/simplified presentation of incredibly complex evaluations (SPICE) provided the most user-friendly manipulations and readable output, evaluating effects of altered antigen-specific stimulation on T cell polyfunctionality. This detailed approach may serve as a model for other investigators/SRLs in selecting the most appropriate software to analyze complex flow cytometry datasets. Further development and awareness of available tools will help guide proper data analysis to answer difficult biologic questions arising from incredibly complex datasets. © Society for Leukocyte Biology.

On the importance of variable soil depth and process representation in the modeling of shallow landslide initiation

NASA Astrophysics Data System (ADS)

Fatichi, S.; Burlando, P.; Anagnostopoulos, G.

2014-12-01

Sub-surface hydrology has a dominant role on the initiation of rainfall-induced landslides, since changes in the soil water potential affect soil shear strength and thus apparent cohesion. Especially on steep slopes and shallow soils, loss of shear strength can lead to failure even in unsaturated conditions. A process based model, HYDROlisthisis, characterized by high resolution in space and, time is developed to investigate the interactions between surface and subsurface hydrology and shallow landslide initiation. Specifically, 3D variably saturated flow conditions, including soil hydraulic hysteresis and preferential flow, are simulated for the subsurface flow, coupled with a surface runoff routine. Evapotranspiration and specific root water uptake are taken into account for continuous simulations of soil water content during storm and inter-storm periods. The geotechnical component of the model is based on a multidimensional limit equilibrium analysis, which takes into account the basic principles of unsaturated soil mechanics. The model is applied to a small catchment in Switzerland historically prone to rainfall-triggered landslides. A series of numerical simulations were carried out with various boundary conditions (soil depths) and using hydrological and geotechnical components of different complexity. Specifically, the sensitivity to the inclusion of preferential flow and soil hydraulic hysteresis was tested together with the replacement of the infinite slope assumption with a multi-dimensional limit equilibrium analysis. The effect of the different model components on model performance was assessed using accuracy statistics and Receiver Operating Characteristic (ROC) curve. The results show that boundary conditions play a crucial role in the model performance and that the introduced hydrological (preferential flow and soil hydraulic hysteresis) and geotechnical components (multidimensional limit equilibrium analysis) considerably improve predictive capabilities in the presented case study.

Validation of the partner version of the multidimensional vaginal penetration disorder questionnaire: A tool for clinical assessment of lifelong vaginismus in a sample of Iranian population.

PubMed

Molaeinezhad, Mitra; Khoei, Effat Merghati; Salehi, Mehrdad; Yousfy, Alireza; Roudsari, Robab Latifnejad

2014-01-01

The role of spousal response in woman's experience of pain during the vaginal penetration attempts believed to be an important factor; however, studies are rather limited in this area. The aim of this study was to develop and investigate the psychometric indexes of the partner version of a multidimensional vaginal penetration disorder questionnaire (PV-MVPDQ); hence, the clinical assessment of spousal psychosexual reactions to vaginismus by specialists will be easier. A mixed-methods sequential exploratory design was used, through that, the findings from a thematic qualitative research with 20 unconsummated couples, which followed by an extensive literature review used for development of PV-MVPDQ. A consecutive sample of 214 men who their wives' suffered from lifelong vaginismus (LLV) based on Diagnostic and Statistical Manual of Mental Disorders 4(th) version (DSM)-IVTR criteria during a cross-sectional design, completed the questionnaire and additional questions regarding their demographic and sexual history. Validation measures and reliability were conducted by exploratory factor analysis (EFA) and Cronbach's alpha coefficient through SPSS version 16 manufactured by SPSS Inc. (IBM corporation, Armonk, USA). After conducting EFA PV-MVPDQ emerged as having 40 items and 7 dimensions: Helplessness, sexual information, vicious cycle of penetration, hypervigilance and solicitous, catastrophic cognitions, sexual and marital adjustment and optimism. Subscales of PV-MVPDQ showed a significant reliability (0.71-0.85) and results of test-retest were satisfactory. The present study shows PV-MVPDQ is a multi-dimensional valid and reliable self-report questionnaire for assessment of cognitions, sexual and marital relations related to vaginal penetrations in spouses of women with LLV. It may assist specialists to base on which clinical judgment and appropriate planning for clinical management.

Validation of the partner version of the multidimensional vaginal penetration disorder questionnaire: A tool for clinical assessment of lifelong vaginismus in a sample of Iranian population

PubMed Central

Molaeinezhad, Mitra; Khoei, Effat Merghati; Salehi, Mehrdad; Yousfy, Alireza; Roudsari, Robab Latifnejad

2014-01-01

Background: The role of spousal response in woman's experience of pain during the vaginal penetration attempts believed to be an important factor; however, studies are rather limited in this area. The aim of this study was to develop and investigate the psychometric indexes of the partner version of a multidimensional vaginal penetration disorder questionnaire (PV-MVPDQ); hence, the clinical assessment of spousal psychosexual reactions to vaginismus by specialists will be easier. Materials and Methods: A mixed-methods sequential exploratory design was used, through that, the findings from a thematic qualitative research with 20 unconsummated couples, which followed by an extensive literature review used for development of PV-MVPDQ. A consecutive sample of 214 men who their wives’ suffered from lifelong vaginismus (LLV) based on Diagnostic and Statistical Manual of Mental Disorders 4th version (DSM)-IVTR criteria during a cross-sectional design, completed the questionnaire and additional questions regarding their demographic and sexual history. Validation measures and reliability were conducted by exploratory factor analysis (EFA) and Cronbach's alpha coefficient through SPSS version 16 manufactured by SPSS Inc. (IBM corporation, Armonk, USA). Results: After conducting EFA PV-MVPDQ emerged as having 40 items and 7 dimensions: Helplessness, sexual information, vicious cycle of penetration, hypervigilance and solicitous, catastrophic cognitions, sexual and marital adjustment and optimism. Subscales of PV-MVPDQ showed a significant reliability (0.71-0.85) and results of test-retest were satisfactory. Conclusion: The present study shows PV-MVPDQ is a multi-dimensional valid and reliable self-report questionnaire for assessment of cognitions, sexual and marital relations related to vaginal penetrations in spouses of women with LLV. It may assist specialists to base on which clinical judgment and appropriate planning for clinical management. PMID:25540787

Why do Ladybugs Smell Bad? In-vivo Quantification of Odorous Insect Kairomones with SPME and Multidimensional GC-MS-Olfactometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai Lingshuang; Koziel, Jacek A.; O'Neal, Matthew E.

2009-05-23

Winemakers, small fruit growers, and homeowners are concerned with noxious compounds released by multicolored Asian ladybird beetles (Harmonia axyridis, Coleoptera: Coccinellidae). New method based on headspace solid phase microextraction (HS-SPME) coupled with multidimensional gas chromatography mass spectrometry--olfactometry (MDGC-MS-O) system was developed for extraction, isolation and simultaneous identification of compounds responsible for the characteristic odor of live H. axyridis. Four methoxypyrazines (MPs) were identified in headspace volatiles of live H. axyridis as those responsible for the characteristic odor: 2, 5-dimethy1-3-methoxypyrazine (DMMP), 2-isopropy1-3-methoxypyrazine (IPMP), 2-sec-buty1-3-methoxypyrazine (SBMP), and 2-isobuty1-3-methoxypyrazine (IBMP). To the best of our knowledge this is the first report of H.more » axyridis releasing DMMP and the first report of this compound being a component of the H. axyridis characteristic odor. Quantification of three MPs (IPMP, SBMP and IBMP) emitted from live H. axyridis were performed using external calibration with HS-SPME and direct injections. A linear relationship (R{sup 2}>0.9958 for all 3 MPs) between MS response and concentration of standard was observed over a concentration range from 0.1 ng L{sup -1} to 0.05 {mu}g L{sup -1} for HS-SPME-GC-MS. The method detection limits (MDL) based on multidimensional GC-MS approach for three MPs were estimated to be between 0.020 ng L{sup -1}. to 0.022 ng L{sup -1}. This methodology is applicable for in vivo determination of odor-causing chemicals associated with emissions of volatiles from insects.« less

HIV Risk and Protection among Gay Male Couples: The Role of Gay Community Integration

ERIC Educational Resources Information Center

Fergus, Stevenson; Lewis, Megan A.; Darbes, Lynae A.; Butterfield, Rita M.

2005-01-01

This study examined the association between different types of integration in the gay community and HIV risk among gay male couples. Previous research linking gay community integration and involvement among couples to HIV risk has been equivocal. Each partner in 59 gay couples completed a separate anonymous questionnaire that assessed two types of…

Optimization of GRIN lenses coupling system for twin-core fiber interconnection with single core fibers

NASA Astrophysics Data System (ADS)

Chen, Gongdai; Deng, Hongchang; Yuan, Libo

2018-07-01

We aim at a more compact, flexible, and simpler core-to-fiber coupling approach, optimal combinations of two graded refractive index (GRIN) lenses have been demonstrated for the interconnection between a twin-core single-mode fiber and two single-core single-mode fibers. The optimal two-lens combinations achieve an efficient core-to-fiber separating coupling and allow the fibers and lenses to coaxially assemble. Finally, axial deviations and transverse displacements of the components are discussed, and the latter increases the coupling loss more significantly. The gap length between the two lenses is designed to be fine-tuned to compensate for the transverse displacement, and the good linear compensation relationship contributes to the device manufacturing. This approach has potential applications in low coupling loss and low crosstalk devices without sophisticated alignment and adjustment, and enables the channel separating for multicore fibers.

Quantitative characterization of gold nanoparticles by field-flow fractionation coupled online with light scattering detection and inductively coupled plasma mass spectrometry.

PubMed

Schmidt, Bjørn; Loeschner, Katrin; Hadrup, Niels; Mortensen, Alicja; Sloth, Jens J; Koch, Christian Bender; Larsen, Erik H

2011-04-01

An analytical platform coupling asymmetric flow field-flow fractionation (AF(4)) with multiangle light scattering (MALS), dynamic light scattering (DLS), and inductively coupled plasma mass spectrometry (ICPMS) was established and used for separation and quantitative determination of size and mass concentration of nanoparticles (NPs) in aqueous suspension. Mixtures of three polystyrene (PS) NPs between 20 and 100 nm in diameter and mixtures of three gold (Au) NPs between 10 and 60 nm in diameter were separated by AF(4). The geometric diameters of the separated PS NPs and the hydrodynamic diameters of the Au and PS NPs were determined online by MALS and DLS, respectively. The three separated Au NPs were quantified by ICPMS and recovered at 50-95% of the injected masses, which ranged between approximately 8-80 ng of each nanoparticle size. Au NPs adhering to the membrane in the separation channel was found to be a major cause for incomplete recoveries. The lower limit of detection (LOD) ranged between 0.02 ng Au and 0.4 ng Au, with increasing LOD by increasing nanoparticle diameter. The analytical platform was applied to characterization of Au NPs in livers of rats, which were dosed with 10 nm, 60 nm, or a mixture of 10 and 60 nm nanoparticles by intravenous injection. The homogenized livers were solubilized in tetramethylammonium hydroxide (TMAH), and the recovery of Au NPs from the livers amounted to 86-123% of their total Au content. In spite of successful stabilization with bovine serum albumin even in alkaline medium, separation of the Au NPs by AF(4) was not possible due to association with undissolved remains of the alkali-treated liver tissues as demonstrated by electron microscopy images.

A Comparative Study of Online Item Calibration Methods in Multidimensional Computerized Adaptive Testing

ERIC Educational Resources Information Center

Chen, Ping

2017-01-01

Calibration of new items online has been an important topic in item replenishment for multidimensional computerized adaptive testing (MCAT). Several online calibration methods have been proposed for MCAT, such as multidimensional "one expectation-maximization (EM) cycle" (M-OEM) and multidimensional "multiple EM cycles"…

Best Design for Multidimensional Computerized Adaptive Testing with the Bifactor Model

ERIC Educational Resources Information Center

Seo, Dong Gi; Weiss, David J.

2015-01-01

Most computerized adaptive tests (CATs) have been studied using the framework of unidimensional item response theory. However, many psychological variables are multidimensional and might benefit from using a multidimensional approach to CATs. This study investigated the accuracy, fidelity, and efficiency of a fully multidimensional CAT algorithm…

Multidimensional Measurement of Poverty among Women in Sub-Saharan Africa

ERIC Educational Resources Information Center

Batana, Yele Maweki

2013-01-01

Since the seminal work of Sen, poverty has been recognized as a multidimensional phenomenon. The recent availability of relevant databases renewed the interest in this approach. This paper estimates multidimensional poverty among women in fourteen Sub-Saharan African countries using the Alkire and Foster multidimensional poverty measures, whose…

The Efficacy of Multidimensional Constraint Keys in Database Query Performance

ERIC Educational Resources Information Center

Cardwell, Leslie K.

2012-01-01

This work is intended to introduce a database design method to resolve the two-dimensional complexities inherent in the relational data model and its resulting performance challenges through abstract multidimensional constructs. A multidimensional constraint is derived and utilized to implement an indexed Multidimensional Key (MK) to abstract a…

C-C Coupling on Single-Atom-Based Heterogeneous Catalyst.

PubMed

Zhang, Xiaoyan; Sun, Zaicheng; Wang, Bin; Tang, Yu; Nguyen, Luan; Li, Yuting; Tao, Franklin Feng

2018-01-24

Compared to homogeneous catalysis, heterogeneous catalysis allows for ready separation of products from the catalyst and thus reuse of the catalyst. C-C coupling is typically performed on a molecular catalyst which is mixed with reactants in liquid phase during catalysis. This homogeneous mixing at a molecular level in the same phase makes separation of the molecular catalyst extremely challenging and costly. Here we demonstrated that a TiO 2 -based nanoparticle catalyst anchoring singly dispersed Pd atoms (Pd 1 /TiO 2 ) is selective and highly active for more than 10 Sonogashira C-C coupling reactions (R≡CH + R'X → R≡R'; X = Br, I; R' = aryl or vinyl). The coupling between iodobenzene and phenylacetylene on Pd 1 /TiO 2 exhibits a turnover rate of 51.0 diphenylacetylene molecules per anchored Pd atom per minute at 60 °C, with a low apparent activation barrier of 28.9 kJ/mol and no cost of catalyst separation. DFT calculations suggest that the single Pd atom bonded to surface lattice oxygen atoms of TiO 2 acts as a site to dissociatively chemisorb iodobenzene to generate an intermediate phenyl, which then couples with phenylacetylenyl bound to a surface oxygen atom. This coupling of phenyl adsorbed on Pd 1 and phenylacetylenyl bound to O ad of TiO 2 forms the product molecule, diphenylacetylene.

On the internal representation of numerical magnitude and physical size.

PubMed

Fitousi, Daniel

2014-01-01

A nascent idea in the numerical cognition literature--the analogical hypothesis (Pinel, Piazza, Bihan, & Dehaene, 2004)--assumes a common noisy code for the representation of symbolic (e.g., numerals) and nonsymbolic (e.g., numerosity, physical size, luminance) magnitudes. The present work subjected this assumption to various tests from the perspective of General Recognition Theory (GRT; Ashby &Townsend, 1986)--a multidimensional extension of Signal Detection Theory (Green & Swets, 1966). The GRT was applied to the dimensions of numerical magnitude and physical size with the following goals: (a) characterizing the internal representation of these dimensions in the psychological space, and (b) assessing various types of (in)dependence and separability governing the perception of these dimensions. The results revealed various violations of independence and separability with Stroop incongruent, but not with Stroop congruent stimuli. The outcome suggests that there are deep differences in architecture between Stroop congruent and incongruent stimuli that reach well beyond the semantic relationship involved.

Non-planar microfabricated gas chromatography column

DOEpatents

Lewis, Patrick R.; Wheeler, David R.

2007-09-25

A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

An exploration of spousal separation and adaptation to long-term disability: six elderly couples engaged in a horticultural programme.

PubMed

Martin, Linda; Miranda, Baldwin; Bean, Michelle

2008-01-01

The main objective of the present study was to explore the impact of separation on couples where one spouse lives in a skilled nursing facility and the other spouse lives alone in the community. Six couples participated in a 10-week gardening group. Semi-structured interviews were conducted at the beginning of the study and observations were made and discussions engaged through the 10-week horticultural programme. Thematic analysis of interviews and discussions revealed reduced social participation of community-dwelling spouses in an effort to maintain their marital role. In one or more cases the non-institutionalized spouse adapted to separation by developing social roles and relationships within the skilled nursing facility and continuing as a caregiver to their spouse. Occupational therapists are encouraged to include spouses in programmes to nurture healthy spousal roles. Further research is needed to explore how elderly couples may support each other through purposeful occupation while one spouse is in a long-term care facility. (c) 2007 John Wiley & Sons, Ltd.

Numerical aspects and implementation of a two-layer zonal wall model for LES of compressible turbulent flows on unstructured meshes

NASA Astrophysics Data System (ADS)

Park, George Ilhwan; Moin, Parviz

2016-01-01

This paper focuses on numerical and practical aspects associated with a parallel implementation of a two-layer zonal wall model for large-eddy simulation (LES) of compressible wall-bounded turbulent flows on unstructured meshes. A zonal wall model based on the solution of unsteady three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations on a separate near-wall grid is implemented in an unstructured, cell-centered finite-volume LES solver. The main challenge in its implementation is to couple two parallel, unstructured flow solvers for efficient boundary data communication and simultaneous time integrations. A coupling strategy with good load balancing and low processors underutilization is identified. Face mapping and interpolation procedures at the coupling interface are explained in detail. The method of manufactured solution is used for verifying the correct implementation of solver coupling, and parallel performance of the combined wall-modeled LES (WMLES) solver is investigated. The method has successfully been applied to several attached and separated flows, including a transitional flow over a flat plate and a separated flow over an airfoil at an angle of attack.

Death Attitudes and Changes in Existential Outlook in Parents of Vulnerable Newborns.

PubMed

Barr, Peter

2015-01-01

This study is an Actor-Partner Interdependence Model analysis of the relation of death attitudes with changes in outlook in 59 parent couples of neonatal intensive care newborns. Death attitudes effects with changes in outlook were mostly intrapersonal and they mainly occurred in fathers, though between gender differences were not usually significant. Death avoidance and neutral death acquiescence were positive predictors of positive changes in outlook, and fear of death and neutral death acquiescence were respective positive and inverse predictors of negative changes. Multidimensional measures of death attitudes and personal change should be used when studying these domains of psychological functioning.

Coherent (photon) vs incoherent (current) detection of multidimensional optical signals from single molecules in open junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwalla, Bijay Kumar; Hua, Weijie; Zhang, Yu

2015-06-07

The nonlinear optical response of a current-carrying single molecule coupled to two metal leads and driven by a sequence of impulsive optical pulses with controllable phases and time delays is calculated. Coherent (stimulated, heterodyne) detection of photons and incoherent detection of the optically induced current are compared. Using a diagrammatic Liouville space superoperator formalism, the signals are recast in terms of molecular correlation functions which are then expanded in the many-body molecular states. Two dimensional signals in benzene-1,4-dithiol molecule show cross peaks involving charged states. The correlation between optical and charge current signal is also observed.

Parameter estimation for chaotic systems using improved bird swarm algorithm

NASA Astrophysics Data System (ADS)

Xu, Chuangbiao; Yang, Renhuan

2017-12-01

Parameter estimation of chaotic systems is an important problem in nonlinear science and has aroused increasing interest of many research fields, which can be basically reduced to a multidimensional optimization problem. In this paper, an improved boundary bird swarm algorithm is used to estimate the parameters of chaotic systems. This algorithm can combine the good global convergence and robustness of the bird swarm algorithm and the exploitation capability of improved boundary learning strategy. Experiments are conducted on the Lorenz system and the coupling motor system. Numerical simulation results reveal the effectiveness and with desirable performance of IBBSA for parameter estimation of chaotic systems.

Current and anticipated uses of thermal-hydraulic codes in Germany

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teschendorff, V.; Sommer, F.; Depisch, F.

1997-07-01

In Germany, one third of the electrical power is generated by nuclear plants. ATHLET and S-RELAP5 are successfully applied for safety analyses of the existing PWR and BWR reactors and possible future reactors, e.g. EPR. Continuous development and assessment of thermal-hydraulic codes are necessary in order to meet present and future needs of licensing organizations, utilities, and vendors. Desired improvements include thermal-hydraulic models, multi-dimensional simulation, computational speed, interfaces to coupled codes, and code architecture. Real-time capability will be essential for application in full-scope simulators. Comprehensive code validation and quantification of uncertainties are prerequisites for future best-estimate analyses.

Inductively coupled plasma-mass spectrometry as an element-specific detector for field-flow fractionation particle separation

USGS Publications Warehouse

Taylor, Howard E.; Garbarino, John R.; Murphy, Deirdre M.; Beckett, Ronald

1992-01-01

An inductively coupled plasma-mass spectrometer was used for the quantitative measurement of trace elements In specific,submicrometer size-fraction particulates, separated by sedimentation field-flow fractionation. Fractions were collected from the eluent of the field-flow fractionation centrifuge and nebulized, with a Babington-type pneumatic nebulizer, into an argon inductively coupled plasma-mass spectrometer. Measured Ion currents were used to quantify the major, minor, and trace element composition of the size-separated colloidal (< 1-microm diameter) particulates. The composition of surface-water suspended matter collected from the Yarra and Darling rivers in Australia is presented to illustrate the usefulness of this tool for characterizing environmental materials. An adsorption experiment was performed using cadmium lon to demonstrate the utility for studying the processes of trace metal-suspended sediment interactions and contaminant transport in natural aquatic systems.

Effect of interstitial palladium on plasmon-driven charge transfer in nanoparticle dimers.

PubMed

Lerch, Sarah; Reinhard, Björn M

2018-04-23

Capacitive plasmon coupling between noble metal nanoparticles (NPs) is characterized by an increasing red-shift of the bonding dipolar plasmon mode (BDP) in the classical electromagnetic coupling regime. This model breaks down at short separations where plasmon-driven charge transfer induces a gap current between the NPs with a magnitude and separation dependence that can be modulated if molecules are present in the gap. Here, we use gap contained DNA as a scaffold for the growth of palladium (Pd) NPs in the gap between two gold NPs and investigate the effect of increasing Pd NP concentration on the BDP mode. Consistent with enhanced plasmon-driven charge transfer, the integration of discrete Pd NPs depolarizes the capacitive BDP mode over longer interparticle separations than is possible in only DNA-linked Au NPs. High Pd NP densities in the gap increases the gap conductance and induces the transition from capacitive to conductive coupling.

Classical-processing and quantum-processing signal separation methods for qubit uncoupling

NASA Astrophysics Data System (ADS)

Deville, Yannick; Deville, Alain

2012-12-01

The Blind Source Separation problem consists in estimating a set of unknown source signals from their measured combinations. It was only investigated in a non-quantum framework up to now. We propose its first quantum extensions. We thus introduce the Quantum Source Separation field, investigating both its blind and non-blind configurations. More precisely, we show how to retrieve individual quantum bits (qubits) only from the global state resulting from their undesired coupling. We consider cylindrical-symmetry Heisenberg coupling, which e.g. occurs when two electron spins interact through exchange. We first propose several qubit uncoupling methods which typically measure repeatedly the coupled quantum states resulting from individual qubits preparations, and which then statistically process the classical data provided by these measurements. Numerical tests prove the effectiveness of these methods. We then derive a combination of quantum gates for performing qubit uncoupling, thus avoiding repeated qubit preparations and irreversible measurements.

Highly efficient peptide separations in proteomics Part 1. Unidimensional high performance liquid chromatography.

PubMed

Sandra, Koen; Moshir, Mahan; D'hondt, Filip; Verleysen, Katleen; Kas, Koen; Sandra, Pat

2008-04-15

Sample complexity and dynamic range constitute enormous challenges in proteome analysis. The back-end technology in typical proteomics platforms, namely mass spectrometry (MS), can only tolerate a certain complexity, has a limited dynamic range per spectrum and is very sensitive towards ion suppression. Therefore, component overlap has to be minimized for successful mass spectrometric analysis and subsequent protein identification and quantification. The present review describes the advances that have been made in liquid-based separation techniques with focus on the recent developments to boost the resolving power. The review is divided in two parts; the first part deals with unidimensional liquid chromatography and the second part with bi- and multidimensional liquid-based separation techniques. Part 1 mainly focuses on reversed-phase HPLC due to the fact that it is and will, in the near future, remain the technique of choice to be hyphenated with MS. The impact of increasing the column length, decreasing the particle diameter, replacing the traditional packed beds by monolithics, amongst others, is described. The review is complemented with data obtained in the laboratories of the authors.

Sustainable water desalination and electricity generation in a separator coupled stacked microbial desalination cell with buffer free electrolyte circulation.

PubMed

Chen, Xi; Liang, Peng; Wei, Zhimou; Zhang, Xiaoyuan; Huang, Xia

2012-09-01

A separator coupled circulation stacked microbial desalination cell (c-SMDC-S) was constructed to stabilize the pH imbalances in MDCs without buffer solution and achieved the stable desalination. The long-term operation of c-SMDC-S, regular stacked MDC (SMDC) and no separator coupled circulation SMDC (c-SMDC) were tested. The SMDC and c-SMDC could only stably operate for 1 week and 1 month owing to dramatic anolyte pH decrease and serious biofilm growth on the air cathode, respectively. The c-SMDC-S gained in anolyte alkalinity and operated stably for about 60 days without the thick biofilm growth on cathode. Besides, the chemical oxygen demand removal and coulombic efficiency were 64 ± 6% and 30 ± 2%, higher than that of SMDC and c-SMDC, respectively. It was concluded that the circulation of alkalinity could remove pH imbalance while the separator could expand the operation period and promote the conversion of organic matter to electricity. Copyright © 2012 Elsevier Ltd. All rights reserved.

FAST TRACK COMMUNICATION: Gyration mode splitting in magnetostatically coupled magnetic vortices in an array

NASA Astrophysics Data System (ADS)

Barman, Anjan; Barman, Saswati; Kimura, T.; Fukuma, Y.; Otani, Y.

2010-10-01

We present the experimental observation of gyration mode splitting by the time-resolved magneto-optical Kerr effect in an array consisting of magnetostatically coupled Ni81Fe19 discs of 1 µm diameter, 50 nm thickness and inter-disc separations varying between 150 and 270 nm. A splitting of the vortex core gyration mode is observed when the inter-disc separation is 200 nm or less and the splitting is controllable by a bias magnetic field. The observed mode splitting is interpreted by micromagnetic simulations as the normal modes of the vortex cores analogous to the coupled classical oscillators. The splitting depends upon the strength of the inter-disc magnetostatic coupling mediated by magnetic side charges, which depends strongly on the magnetic ground states of the samples.

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

PubMed Central

Maddi, Balakrishna; Panisko, Ellen; Albrecht, Karl; Howe, Daniel

2016-01-01

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessaryprior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted. PMID:27022829

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry.

PubMed

Maddi, Balakrishna; Panisko, Ellen; Albrecht, Karl; Howe, Daniel

2016-03-06

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessary prior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.

A comparative analysis of the categorization of multidimensional stimuli: I. Unidimensional classification does not necessarily imply analytic processing; evidence from pigeons (Columba livia), squirrels (Sciurus carolinensis), and humans (Homo sapiens).

PubMed

Wills, A J; Lea, Stephen E G; Leaver, Lisa A; Osthaus, Britta; Ryan, Catriona M E; Suret, Mark B; Bryant, Catherine M L; Chapman, Sue J A; Millar, Louise

2009-11-01

Pigeons (Columba livia), gray squirrels (Sciurus carolinensis), and undergraduates (Homo sapiens) learned discrimination tasks involving multiple mutually redundant dimensions. First, pigeons and undergraduates learned conditional discriminations between stimuli composed of three spatially separated dimensions, after first learning to discriminate the individual elements of the stimuli. When subsequently tested with stimuli in which one of the dimensions took an anomalous value, the majority of both species categorized test stimuli by their overall similarity to training stimuli. However some individuals of both species categorized them according to a single dimension. In a second set of experiments, squirrels, pigeons, and undergraduates learned go/no-go discriminations using multiple simultaneous presentations of stimuli composed of three spatially integrated, highly salient dimensions. The tendency to categorize test stimuli including anomalous dimension values unidimensionally was higher than in the first set of experiments and did not differ significantly between species. The authors conclude that unidimensional categorization of multidimensional stimuli is not diagnostic for analytic cognitive processing, and that any differences between human's and pigeons' behavior in such tasks are not due to special features of avian visual cognition.

I am AmeriBritSouthAfrican-Zambian: Multidimensional remote acculturation and well-being among urban Zambian adolescents.

PubMed

Ferguson, Yuna L; Ferguson, Kim T; Ferguson, Gail M

2017-02-01

One impact of globalisation is that adolescents today are frequently exposed to the values, attitudes and norms of other nations without leaving their own backyards. This may lead to remote acculturation-cultural and psychological changes experienced by non-migrant individuals having indirect and/or intermittent contact with a geographically separate culture. Using quantitative and qualitative data, we examined multidimensional remote acculturation among 83 urban Zambian adolescents who are routinely exposed to U.S., U.K. and South African cultures through traditional and social media and materials/goods. Cluster analyses showed 2 distinct groups of adolescents. "Traditional Zambians, TZs" (55.4%) were significantly more oriented towards Zambian culture and reported a higher level of obligation to their families and greater interdependent self-construal compared with "Westernised Multicultural Zambians, WMZs" (44.6%), who were more oriented towards U.S., U.K. and South African cultures. Furthermore, remote acculturation predicted somewhat lower life satisfaction among WMZs. These results demonstrate that individuals' behaviours, values and identity may be influenced by multiple geographically distant cultures simultaneously and may be associated with psychological costs. © 2015 International Union of Psychological Science.

Fluorescence Intrinsic Characterization of Excitation-Emission Matrix Using Multi-Dimensional Ensemble Empirical Mode Decomposition

PubMed Central

Chang, Chi-Ying; Chang, Chia-Chi; Hsiao, Tzu-Chien

2013-01-01

Excitation-emission matrix (EEM) fluorescence spectroscopy is a noninvasive method for tissue diagnosis and has become important in clinical use. However, the intrinsic characterization of EEM fluorescence remains unclear. Photobleaching and the complexity of the chemical compounds make it difficult to distinguish individual compounds due to overlapping features. Conventional studies use principal component analysis (PCA) for EEM fluorescence analysis, and the relationship between the EEM features extracted by PCA and diseases has been examined. The spectral features of different tissue constituents are not fully separable or clearly defined. Recently, a non-stationary method called multi-dimensional ensemble empirical mode decomposition (MEEMD) was introduced; this method can extract the intrinsic oscillations on multiple spatial scales without loss of information. The aim of this study was to propose a fluorescence spectroscopy system for EEM measurements and to describe a method for extracting the intrinsic characteristics of EEM by MEEMD. The results indicate that, although PCA provides the principal factor for the spectral features associated with chemical compounds, MEEMD can provide additional intrinsic features with more reliable mapping of the chemical compounds. MEEMD has the potential to extract intrinsic fluorescence features and improve the detection of biochemical changes. PMID:24240806

Multi-dimensional SAR tomography for monitoring the deformation of newly built concrete buildings

NASA Astrophysics Data System (ADS)

Ma, Peifeng; Lin, Hui; Lan, Hengxing; Chen, Fulong

2015-08-01

Deformation often occurs in buildings at early ages, and the constant inspection of deformation is of significant importance to discover possible cracking and avoid wall failure. This paper exploits the multi-dimensional SAR tomography technique to monitor the deformation performances of two newly built buildings (B1 and B2) with a special focus on the effects of concrete creep and shrinkage. To separate the nonlinear thermal expansion from total deformations, the extended 4-D SAR technique is exploited. The thermal map estimated from 44 TerraSAR-X images demonstrates that the derived thermal amplitude is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that B1 is subject to settlement during the construction period, in addition, the creep and shrinkage of B1 lead to wall shortening that is a height-dependent movement in the downward direction, and the asymmetrical creep of B2 triggers wall deflection that is a height-dependent movement in the deflection direction. It is also validated that the extended 4-D SAR can rectify the bias of estimated wall shortening and wall deflection by 4-D SAR.

Application of random coherence order selection in gradient-enhanced multidimensional NMR

NASA Astrophysics Data System (ADS)

Bostock, Mark J.; Nietlispach, Daniel

2016-03-01

Development of multidimensional NMR is essential to many applications, for example in high resolution structural studies of biomolecules. Multidimensional techniques enable separation of NMR signals over several dimensions, improving signal resolution, whilst also allowing identification of new connectivities. However, these advantages come at a significant cost. The Fourier transform theorem requires acquisition of a grid of regularly spaced points to satisfy the Nyquist criterion, while frequency discrimination and acquisition of a pure phase spectrum require acquisition of both quadrature components for each time point in every indirect (non-acquisition) dimension, adding a factor of 2 N -1 to the number of free- induction decays which must be acquired, where N is the number of dimensions. Compressed sensing (CS) ℓ 1-norm minimisation in combination with non-uniform sampling (NUS) has been shown to be extremely successful in overcoming the Nyquist criterion. Previously, maximum entropy reconstruction has also been used to overcome the limitation of frequency discrimination, processing data acquired with only one quadrature component at a given time interval, known as random phase detection (RPD), allowing a factor of two reduction in the number of points for each indirect dimension (Maciejewski et al. 2011 PNAS 108 16640). However, whilst this approach can be easily applied in situations where the quadrature components are acquired as amplitude modulated data, the same principle is not easily extended to phase modulated (P-/N-type) experiments where data is acquired in the form exp (iωt) or exp (-iωt), and which make up many of the multidimensional experiments used in modern NMR. Here we demonstrate a modification of the CS ℓ 1-norm approach to allow random coherence order selection (RCS) for phase modulated experiments; we generalise the nomenclature for RCS and RPD as random quadrature detection (RQD). With this method, the power of RQD can be extended to the full suite of experiments available to modern NMR spectroscopy, allowing resolution enhancements for all indirect dimensions; alone or in combination with NUS, RQD can be used to improve experimental resolution, or shorten experiment times, of considerable benefit to the challenging applications undertaken by modern NMR.

Probing Excited States in Nuclei at and Beyond the Proton Drip-Line

NASA Astrophysics Data System (ADS)

Carpenter, Michael P.

1999-03-01

The coupling of a Compton-suppressed Ge (CSGe) detector array to a recoil separator has seen limited use in the past due to the low efficiency for measuring recoil-γ ray coincidences (<0.1% ). With the building of new generation recoil separators and gamma-ray arrays, a substantial increase in detection efficiency has been achieved. This allows for the opportunity to measure excited states in nuclei with cross-sections below 100 nb. In this paper, results from the coupling of a modest array of CSGe detectors (AYE-Ball) and a current generation Ge array (Gammasphere) with a recoil separator (FMA) will be presented.

Accessing Multi-Dimensional Images and Data Cubes in the Virtual Observatory

NASA Astrophysics Data System (ADS)

Tody, Douglas; Plante, R. L.; Berriman, G. B.; Cresitello-Dittmar, M.; Good, J.; Graham, M.; Greene, G.; Hanisch, R. J.; Jenness, T.; Lazio, J.; Norris, P.; Pevunova, O.; Rots, A. H.

2014-01-01

Telescopes across the spectrum are routinely producing multi-dimensional images and datasets, such as Doppler velocity cubes, polarization datasets, and time-resolved “movies.” Examples of current telescopes producing such multi-dimensional images include the JVLA, ALMA, and the IFU instruments on large optical and near-infrared wavelength telescopes. In the near future, both the LSST and JWST will also produce such multi-dimensional images routinely. High-energy instruments such as Chandra produce event datasets that are also a form of multi-dimensional data, in effect being a very sparse multi-dimensional image. Ensuring that the data sets produced by these telescopes can be both discovered and accessed by the community is essential and is part of the mission of the Virtual Observatory (VO). The Virtual Astronomical Observatory (VAO, http://www.usvao.org/), in conjunction with its international partners in the International Virtual Observatory Alliance (IVOA), has developed a protocol and an initial demonstration service designed for the publication, discovery, and access of arbitrarily large multi-dimensional images. The protocol describing multi-dimensional images is the Simple Image Access Protocol, version 2, which provides the minimal set of metadata required to characterize a multi-dimensional image for its discovery and access. A companion Image Data Model formally defines the semantics and structure of multi-dimensional images independently of how they are serialized, while providing capabilities such as support for sparse data that are essential to deal effectively with large cubes. A prototype data access service has been deployed and tested, using a suite of multi-dimensional images from a variety of telescopes. The prototype has demonstrated the capability to discover and remotely access multi-dimensional data via standard VO protocols. The prototype informs the specification of a protocol that will be submitted to the IVOA for approval, with an operational data cube service to be delivered in mid-2014. An associated user-installable VO data service framework will provide the capabilities required to publish VO-compatible multi-dimensional images or data cubes.

Fluid coupling in a discrete model of cochlear mechanics.

PubMed

Elliott, Stephen J; Lineton, Ben; Ni, Guangjian

2011-09-01

A discrete model of cochlear mechanics is introduced that includes a full, three-dimensional, description of fluid coupling. This formulation allows the fluid coupling and basilar membrane dynamics to be analyzed separately and then coupled together with a simple piece of linear algebra. The fluid coupling is initially analyzed using a wavenumber formulation and is separated into one component due to one-dimensional fluid coupling and one comprising all the other contributions. Using the theory of acoustic waves in a duct, however, these two components of the pressure can also be associated with a far field, due to the plane wave, and a near field, due to the evanescent, higher order, modes. The near field components are then seen as one of a number of sources of additional longitudinal coupling in the cochlea. The effects of non-uniformity and asymmetry in the fluid chamber areas can also be taken into account, to predict both the pressure difference between the chambers and the mean pressure. This allows the calculation, for example, of the effect of a short cochlear implant on the coupled response of the cochlea. © 2011 Acoustical Society of America

A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction.

PubMed

Gao, Yang; Li, Hongsheng; Huang, Libin; Sun, Hui

2017-04-30

This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope's modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity.

Enhancing Bottom-up and Top-down Proteomic Measurements with Ion Mobility Separations

DOE PAGES

Baker, Erin Shammel; Burnum-Johnson, Kristin E.; Ibrahim, Yehia M.; ...

2015-07-03

Proteomic measurements with greater throughput, sensitivity and additional structural information enhance the in-depth characterization of complex mixtures and targeted studies with additional information and higher confidence. While liquid chromatography separation coupled with mass spectrometry (LC-MS) measurements have provided information on thousands of proteins in different sample types, the additional of another rapid separation stage providing structural information has many benefits for analyses. Technical advances in ion funnels and multiplexing have enabled ion mobility separations to be easily and effectively coupled with LC-MS proteomics to enhance the information content of measurements. Finally, herein, we report on applications illustrating increased sensitivity, throughput,more » and structural information by utilizing IMS-MS and LC-IMS-MS measurements for both bottom-up and top-down proteomics measurements.« less

Solution structure of the DNA-binding domain of the heat shock transcription factor determined by multidimensional heteronuclear magnetic resonance spectroscopy.

PubMed Central

Damberger, F. F.; Pelton, J. G.; Harrison, C. J.; Nelson, H. C.; Wemmer, D. E.

1994-01-01

The solution structure of the 92-residue DNA-binding domain of the heat shock transcription factor from Kluyveromyces lactis has been determined using multidimensional NMR methods. Three-dimensional (3D) triple resonance, 1H-13C-13C-1H total correlation spectroscopy, and 15N-separated total correlation spectroscopy-heteronuclear multiple quantum correlation experiments were used along with various 2D spectra to make nearly complete assignments for the backbone and side-chain 1H, 15N, and 13C resonances. Five-hundred eighty-three NOE constraints identified in 3D 13C- and 15N-separated NOE spectroscopy (NOESY)-heteronuclear multiple quantum correlation spectra and a 4-dimensional 13C/13C-edited NOESY spectrum, along with 35 phi, 9 chi 1, and 30 hydrogen bond constraints, were used to calculate 30 structures by hybrid distance geometry/stimulated annealing protocol, of which 24 were used for structural comparison. The calculations revealed that a 3-helix bundle packs against a small 4-stranded antiparallel beta-sheet. The backbone RMS deviation (RMSD) for the family of structures was 1.03 +/- 0.19 A with respect to the average structure. The topology is analogous to that of the C-terminal domain of the catabolite gene activator protein and appears to be in the helix-turn-helix family of DNA-binding proteins. The overall fold determined by the NMR data is consistent with recent crystallographic work on this domain (Harrison CJ, Bohm AA, Nelson HCM, 1994, Science 263:224) as evidenced by RMSD between backbone atoms in the NMR and X-ray structures of 1.77 +/- 0.20 A. Several differences were identified some of which may be due to protein-protein interactions in the crystal. PMID:7849597

20 CFR 416.520 - Emergency advance payments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of expected eligibility for payment of benefits. (2) For a couple, we separately compute each member... not established. If a presumptively eligible individual (or spouse) or couple is determined to be...

Autonomous self-configuration of artificial neural networks for data classification or system control

NASA Astrophysics Data System (ADS)

Fink, Wolfgang

2009-05-01

Artificial neural networks (ANNs) are powerful methods for the classification of multi-dimensional data as well as for the control of dynamic systems. In general terms, ANNs consist of neurons that are, e.g., arranged in layers and interconnected by real-valued or binary neural couplings or weights. ANNs try mimicking the processing taking place in biological brains. The classification and generalization capabilities of ANNs are given by the interconnection architecture and the coupling strengths. To perform a certain classification or control task with a particular ANN architecture (i.e., number of neurons, number of layers, etc.), the inter-neuron couplings and their accordant coupling strengths must be determined (1) either by a priori design (i.e., manually) or (2) using training algorithms such as error back-propagation. The more complex the classification or control task, the less obvious it is how to determine an a priori design of an ANN, and, as a consequence, the architecture choice becomes somewhat arbitrary. Furthermore, rather than being able to determine for a given architecture directly the corresponding coupling strengths necessary to perform the classification or control task, these have to be obtained/learned through training of the ANN on test data. We report on the use of a Stochastic Optimization Framework (SOF; Fink, SPIE 2008) for the autonomous self-configuration of Artificial Neural Networks (i.e., the determination of number of hidden layers, number of neurons per hidden layer, interconnections between neurons, and respective coupling strengths) for performing classification or control tasks. This may provide an approach towards cognizant and self-adapting computing architectures and systems.

Multidimensional Unfolding by Nonmetric Multidimensional Scaling of Spearman Distances in the Extended Permutation Polytope

ERIC Educational Resources Information Center

Van Deun, Katrijn; Heiser, Willem J.; Delbeke, Luc

2007-01-01

A multidimensional unfolding technique that is not prone to degenerate solutions and is based on multidimensional scaling of a complete data matrix is proposed: distance information about the unfolding data and about the distances both among judges and among objects is included in the complete matrix. The latter information is derived from the…

Measuring Global Physical Health in Children with Cerebral Palsy: Illustration of a Multidimensional Bi-factor Model and Computerized Adaptive Testing

PubMed Central

Haley, Stephen M.; Ni, Pengsheng; Dumas, Helene M.; Fragala-Pinkham, Maria A.; Hambleton, Ronald K.; Montpetit, Kathleen; Bilodeau, Nathalie; Gorton, George E.; Watson, Kyle; Tucker, Carole A

2009-01-01

Purpose The purpose of this study was to apply a bi-factor model for the determination of test dimensionality and a multidimensional CAT using computer simulations of real data for the assessment of a new global physical health measure for children with cerebral palsy (CP). Methods Parent respondents of 306 children with cerebral palsy were recruited from four pediatric rehabilitation hospitals and outpatient clinics. We compared confirmatory factor analysis results across four models: (1) one-factor unidimensional; (2) two-factor multidimensional (MIRT); (3) bi-factor MIRT with fixed slopes; and (4) bi-factor MIRT with varied slopes. We tested whether the general and content (fatigue and pain) person score estimates could discriminate across severity and types of CP, and whether score estimates from a simulated CAT were similar to estimates based on the total item bank, and whether they correlated as expected with external measures. Results Confirmatory factor analysis suggested separate pain and fatigue sub-factors; all 37 items were retained in the analyses. From the bi-factor MIRT model with fixed slopes, the full item bank scores discriminated across levels of severity and types of CP, and compared favorably to external instruments. CAT scores based on 10- and 15-item versions accurately captured the global physical health scores. Conclusions The bi-factor MIRT CAT application, especially the 10- and 15-item version, yielded accurate global physical health scores that discriminated across known severity groups and types of CP, and correlated as expected with concurrent measures. The CATs have potential for collecting complex data on the physical health of children with CP in an efficient manner. PMID:19221892

The Effect of Emotional Focused Intervention on Spousal Emotional Abuse and Marital Satisfaction among Elderly Married Couples: A Randomized Controlled Trial.

PubMed

Hazrati, Maryam; Hamid, Tengku Aizan; Ibrahim, Rahimah; Hassan, Siti Aishah; Sharif, Farkhondeh; Bagheri, Zahra

2017-10-01

This study examined the impacts of an Emotional Focused Intervention on emotional abuse behaviors and marital satisfaction among the elderly married couples. This randomized controlled trial study was carried out in Shiraz-Iran, during September 2013-2014. The elderly couples were invited to join an emotional focused intervention, following the advertisement and announcement on bulletin boards in the elderly day clinic centers and all governmental primary health care centers. Then, 57 couples (114 participants) who were eligible for study were assigned in two groups by block randomization (29 in the experimental and 28 in the control group(.The couples in the experimental group received intervention twice a week for four weeks. Each session lasted 90 minutes. The control group didn't receive any intervention and the subjects were put in the waiting list. The outcome measures were evaluated by Multidimensional Measure of Emotional Abuse Questionnaire (MMEAQ) and Marital Satisfaction Questionnaire for Older People (MSQFOP). Repeated measurement ANOVA was used to detect any significant changes between groups in their mean scores of emotional abuse behaviors and marital satisfaction from pre- to post-test, and 3 months after the intervention. Analysis of data was performed using SPSS, version 19, and P≤0.05 was measured as significant. The mean duration of marriage was 39.56±9.64 years. In the experimental group, the abusive behaviors decreased significantly (P<0.001) at times 2 and 3 compared with time 1, and marital satisfaction improved significantly only at time 3 (P<0.001). These differences were not significant in the control group. Emotion-focused couple-based interventions are helpful in reducing the spousal emotional abuse and improving marital satisfaction in among the elderly couples. Trial Registration Number: 2013111715426N1.

On operational flood forecasting system involving 1D/2D coupled hydraulic model and data assimilation

NASA Astrophysics Data System (ADS)

Barthélémy, S.; Ricci, S.; Morel, T.; Goutal, N.; Le Pape, E.; Zaoui, F.

2018-07-01

In the context of hydrodynamic modeling, the use of 2D models is adapted in areas where the flow is not mono-dimensional (confluence zones, flood plains). Nonetheless the lack of field data and the computational cost constraints limit the extensive use of 2D models for operational flood forecasting. Multi-dimensional coupling offers a solution with 1D models where the flow is mono-dimensional and with local 2D models where needed. This solution allows for the representation of complex processes in 2D models, while the simulated hydraulic state is significantly better than that of the full 1D model. In this study, coupling is implemented between three 1D sub-models and a local 2D model for a confluence on the Adour river (France). A Schwarz algorithm is implemented to guarantee the continuity of the variables at the 1D/2D interfaces while in situ observations are assimilated in the 1D sub-models to improve results and forecasts in operational mode as carried out by the French flood forecasting services. An implementation of the coupling and data assimilation (DA) solution with domain decomposition and task/data parallelism is proposed so that it is compatible with operational constraints. The coupling with the 2D model improves the simulated hydraulic state compared to a global 1D model, and DA improves results in 1D and 2D areas.

Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jinsu; Ko, Pyungwon; Park, Wan-Il, E-mail: kimjinsu@kias.re.kr, E-mail: pko@kias.re.kr, E-mail: Wanil.Park@uv.es

We show that the Higgs portal interactions involving extra dark Higgs field can save generically the original Higgs inflation of the standard model (SM) from the problem of a deep non-SM vacuum in the SM Higgs potential. Specifically, we show that such interactions disconnect the top quark pole mass from inflationary observables and allow multi-dimensional parameter space to save the Higgs inflation, thanks to the additional parameters (the dark Higgs boson mass m {sub φ}, the mixing angle α between the SM Higgs H and dark Higgs Φ, and the mixed quartic coupling) affecting RG-running of the Higgs quartic coupling.more » The effect of Higgs portal interactions may lead to a larger tensor-to-scalar ratio, 0.08 ∼< r ∼< 0.1, by adjusting relevant parameters in wide ranges of α and m {sub φ}, some region of which can be probed at future colliders. Performing a numerical analysis we find an allowed region of parameters, matching the latest Planck data.« less

Role of temperature dependence of optical properties in laser irradiation of biological tissue

NASA Astrophysics Data System (ADS)

Rastegar, Sohi; Kim, Beop-Min; Jacques, Steven L.

1992-08-01

Optical properties of biological tissue can change as a result of thermal denaturation due to temperature rise; a familiar example is whitening observed in cooking egg-white. Changes in optical properties with temperature have been reported in the literature. Temperature rise due to laser irradiation is a function of the optical properties of tissue which themselves are a function of temperature of the tissue. This creates a coupling between light and temperature fields for biological tissue under laser irradiation. The effects of this coupling on the temperature response and light distribution may play an important role in dosimetry consideration for therapeutic as well as diagnostic application of lasers in medicine. In a previous study this problem was addressed in one dimension, for short irradiation exposures, using certain simplifying assumptions. The purpose of this research was to develop a mathematical model for dynamic optical changes with thermal denaturation and a computer program for simulation of these effects for a multi-dimensional geometry.

Groundwater flow and heat transport for systems undergoing freeze-thaw: Intercomparison of numerical simulators for 2D test cases

NASA Astrophysics Data System (ADS)

Grenier, Christophe; Anbergen, Hauke; Bense, Victor; Chanzy, Quentin; Coon, Ethan; Collier, Nathaniel; Costard, François; Ferry, Michel; Frampton, Andrew; Frederick, Jennifer; Gonçalvès, Julio; Holmén, Johann; Jost, Anne; Kokh, Samuel; Kurylyk, Barret; McKenzie, Jeffrey; Molson, John; Mouche, Emmanuel; Orgogozo, Laurent; Pannetier, Romain; Rivière, Agnès; Roux, Nicolas; Rühaak, Wolfram; Scheidegger, Johanna; Selroos, Jan-Olof; Therrien, René; Vidstrand, Patrik; Voss, Clifford

2018-04-01

In high-elevation, boreal and arctic regions, hydrological processes and associated water bodies can be strongly influenced by the distribution of permafrost. Recent field and modeling studies indicate that a fully-coupled multidimensional thermo-hydraulic approach is required to accurately model the evolution of these permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require verification. This issue is addressed by means of an intercomparison of thirteen numerical codes for two-dimensional test cases with several performance metrics (PMs). These codes comprise a wide range of numerical approaches, spatial and temporal discretization strategies, and computational efficiencies. Results suggest that the codes provide robust results for the test cases considered and that minor discrepancies are explained by computational precision. However, larger discrepancies are observed for some PMs resulting from differences in the governing equations, discretization issues, or in the freezing curve used by some codes.

Origin of the magnetic-field controlled polarization reversal in multiferroic TbMn2 O 5

NASA Astrophysics Data System (ADS)

Leo, N.; Meier, D.; Pisarev, R. V.; Park, S.; Cheong, S.-W.; Fiebig, M.

2011-03-01

The interplay of multi-dimensional complex magnetic order parameters leads to interesting effects like magnetically induced ferroelectricity. A particular interesting example is TbMn 2 O5 because of the associated magnetic-field controllable electric polarization. By optical second harmonic generation we show that the gigantic magnetoelectric effect originates in three independent ferroelectric contributions. Two of these are manganese-generated. The third contribution is related to the magnetism of the Tb 3+ sublattice and has not been identified so far. It mediates the remarkable magnetic-field induced polarization reversal. This model is verified by experiments on the isostructural YMn 2 O5 where Y3+ ions are nonmagnetic and only two polarization contributions are present and no magnetoelectric coupling is observed. These results underline the importance of the 3 d - 4 f -interaction for the intricate magnetoelectric coupling in the class of isostructural RMn 2 O5 compounds. This work was supported by the DFG through SFB 608.

Stepwise calibration procedure for regional coupled hydrological-hydrogeological models

NASA Astrophysics Data System (ADS)

Labarthe, Baptiste; Abasq, Lena; de Fouquet, Chantal; Flipo, Nicolas

2014-05-01

Stream-aquifer interaction is a complex process depending on regional and local processes. Indeed, the groundwater component of hydrosystem and large scale heterogeneities control the regional flows towards the alluvial plains and the rivers. In second instance, the local distribution of the stream bed permeabilities controls the dynamics of stream-aquifer water fluxes within the alluvial plain, and therefore the near-river piezometric head distribution. In order to better understand the water circulation and pollutant transport in watersheds, the integration of these multi-dimensional processes in modelling platform has to be performed. Thus, the nested interfaces concept in continental hydrosystem modelling (where regional fluxes, simulated by large scale models, are imposed at local stream-aquifer interfaces) has been presented in Flipo et al (2014). This concept has been implemented in EauDyssée modelling platform for a large alluvial plain model (900km2) part of a 11000km2 multi-layer aquifer system, located in the Seine basin (France). The hydrosystem modelling platform is composed of four spatially distributed modules (Surface, Sub-surface, River and Groundwater), corresponding to four components of the terrestrial water cycle. Considering the large number of parameters to be inferred simultaneously, the calibration process of coupled models is highly computationally demanding and therefore hardly applicable to a real case study of 10000km2. In order to improve the efficiency of the calibration process, a stepwise calibration procedure is proposed. The stepwise methodology involves determining optimal parameters of all components of the coupled model, to provide a near optimum prior information for the global calibration. It starts with the surface component parameters calibration. The surface parameters are optimised based on the comparison between simulated and observed discharges (or filtered discharges) at various locations. Once the surface parameters have been determined, the groundwater component is calibrated. The calibration procedure is performed under steady state hypothesis (to minimize the procedure time length) using recharge rates given by the surface component calibration and imposed fluxes boundary conditions given by the regional model. The calibration is performed using pilot point where the prior variogram is calculated from observed transmissivities values. This procedure uses PEST (http//:www.pesthomepage.org/Home.php) as the inverse modelling tool and EauDyssée as the direct model. During the stepwise calibration process, each modules, even if they are actually dependant from each other, are run and calibrated independently, therefore contributions between each module have to be determined. For the surface module, groundwater and runoff contributions have been determined by hydrograph separation. Among the automated base-flow separation methods, the one-parameter Chapman filter (Chapman et al 1999) has been chosen. This filter is a decomposition of the actual base-flow between the previous base-flow and the discharge gradient weighted by functions of the recession coefficient. For the groundwater module, the recharge has been determined from surface and sub-surface module. References : Flipo, N., A. Mourhi, B. Labarthe, and S. Biancamaria (2014). Continental hydrosystem modelling : the concept of nested stream-aquifer interfaces. Hydrol. Earth Syst. Sci. Discuss. 11, 451-500. Chapman,TG. (1999). A comparison of algorithms for stream flow recession and base-flow separation. hydrological Processes 13, 701-714.

Direction selective structural-acoustic coupled radiator

NASA Astrophysics Data System (ADS)

Seo, Hee-Seon; Kim, Yang-Hann

2005-04-01

This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

Coupling of Spinosad Fermentation and Separation Process via Two-Step Macroporous Resin Adsorption Method.

PubMed

Zhao, Fanglong; Zhang, Chuanbo; Yin, Jing; Shen, Yueqi; Lu, Wenyu

2015-08-01

In this paper, a two-step resin adsorption technology was investigated for spinosad production and separation as follows: the first step resin addition into the fermentor at early cultivation period to decrease the timely product concentration in the broth; the second step of resin addition was used after fermentation to adsorb and extract the spinosad. Based on this, a two-step macroporous resin adsorption-membrane separation process for spinosad fermentation, separation, and purification was established. Spinosad concentration in 5-L fermentor increased by 14.45 % after adding 50 g/L macroporous at the beginning of fermentation. The established two-step macroporous resin adsorption-membrane separation process got the 95.43 % purity and 87 % yield for spinosad, which were both higher than that of the conventional crystallization of spinosad from aqueous phase that were 93.23 and 79.15 % separately. The two-step macroporous resin adsorption method has not only carried out the coupling of spinosad fermentation and separation but also increased spinosad productivity. In addition, the two-step macroporous resin adsorption-membrane separation process performs better in spinosad yield and purity.

Ferromagnetic resonance in coupled permalloy double films separated by a Cu interlayer

NASA Astrophysics Data System (ADS)

Maksymowicz, A. Z.; Whiting, J. S. S.; Watson, M. L.; Chambers, A.

1991-03-01

Ferromagnetic resonance (FMR) at 16 GHz was used to study the magnetic coupling between two-layers of permalloy separated by a nonmagnetic Cu layer. Samples with the same thickness (600 Å) of both permalloy layers were deposited from e-gun sources onto glass substrates in UHV. The thickness d of the Cu interlayer was varied from 5 to 37 Å. The exchange coupling energy ( E = - KM1· M2) model was used to describe the interaction between the two magnetic layers. It was found from the ferromagnetic resonance data in the perpendicular configuration that K( d) follows an exponential law, K = K0e - d/ q, where q = 9.3 Å.

Coupling analysis of non-circular-symmetric modes and design of orientation-insensitive few-mode fiber couplers

NASA Astrophysics Data System (ADS)

Li, Jiaxiong; Du, Jiangbing; Ma, Lin; Li, Ming-Jun; Jiang, Shoulin; Xu, Xiao; He, Zuyuan

2017-01-01

We study the coupling between two identical weakly-coupled few-mode fibers based on coupled-mode theory. The coupling behavior of non-circular-symmetric modes, such as LP11 and LP21, is investigated analytically and numerically. By carefully choosing the fiber core separation and coupler length, we can design orientation-insensitive fiber couplers for non-circular-symmetric modes at arbitrary coupling ratios. Based on the design method, we propose an orientation-insensitive two-mode fiber coupler at 850 nm working as a mode multiplexer/demultiplexer for two-mode transmission using standard single-mode fiber. Within the band from 845 to 855 nm, the insertion losses of LP01 and LP11 modes are less than 0.03 dB and 0.24 dB, respectively. When the two-mode fiber coupler is used as mode demultiplexer, the LP01/LP11 and LP11/LP01 extinction ratios in the separated branches are respectively above 12.6 dB and 21.2 dB. Our design method can be extended to two-mode communication or sensing systems at other wavelengths.

Dynamical network of residue–residue contacts reveals coupled allosteric effects in recognition, catalysis, and mutation

PubMed Central

Doshi, Urmi; Holliday, Michael J.; Eisenmesser, Elan Z.; Hamelberg, Donald

2016-01-01

Detailed understanding of how conformational dynamics orchestrates function in allosteric regulation of recognition and catalysis remains ambiguous. Here, we simulate CypA using multiple-microsecond-long atomistic molecular dynamics in explicit solvent and carry out NMR experiments. We analyze a large amount of time-dependent multidimensional data with a coarse-grained approach and map key dynamical features within individual macrostates by defining dynamics in terms of residue–residue contacts. The effects of substrate binding are observed to be largely sensed at a location over 15 Å from the active site, implying its importance in allostery. Using NMR experiments, we confirm that a dynamic cluster of residues in this distal region is directly coupled to the active site. Furthermore, the dynamical network of interresidue contacts is found to be coupled and temporally dispersed, ranging over 4 to 5 orders of magnitude. Finally, using network centrality measures we demonstrate the changes in the communication network, connectivity, and influence of CypA residues upon substrate binding, mutation, and during catalysis. We identify key residues that potentially act as a bottleneck in the communication flow through the distinct regions in CypA and, therefore, as targets for future mutational studies. Mapping these dynamical features and the coupling of dynamics to function has crucial ramifications in understanding allosteric regulation in enzymes and proteins, in general. PMID:27071107

[Treating vaginismus in Turkish women].

PubMed

Gül, V; Ruf, G D

2009-03-01

Vaginismus is a sexual dysfunction involving various branches of medicine, including psychiatry and gynaecology. Psychiatric help is sought in only a small proportion of cases, although it is probable that the psychopathological aetiology is more frequent than generally recognized. This article deals with the causes and psychological circumstances in four Turkish couples who presented with unconsummated marriage for 3 to 7 years. Vaginismus F52.5 to the ICD-10 is a sexual dysfunction characterised as: deep anxiety about coitus leading to extreme spasm of musculature making coitus impossible or extremely unpleasant and painful. Four Turkish couples with unconsummated marriage due to the female partners' penetration phobia were included to this study. A patient-oriented multidimensional individual treatment (combination therapy) is a cost effective, short-term (typically 10- to 12-week) treatment model for both partners. It includes some elements of cognitive behavioural therapy and systemic partner therapy which were considered not radically different from previous therapeutic strategies. Results were successful in all cases; the couples were extremely satisfied with having a normal sex life for the first time. This led to desired pregnancies and avoiding of possible breakdown of their families. The couples did well with combination behavioural therapy. This methodology is discussed in its various aspects and with a cultural background. We also emphasise the need for physicians to be mindful of cases of vaginismus requiring psychiatric intervention rather than gynaecological treatment.

Analytical Applications of Transport Through Bulk Liquid Membranes.

PubMed

Diaconu, Ioana; Ruse, Elena; Aboul-Enein, Hassan Y; Bunaciu, Andrei A

2016-07-03

This review discusses the results of research in the use of bulk liquid membranes in separation processes and preconcentration for analytical purposes. It includes some theoretical aspects, definitions, types of liquid membranes, and transport mechanism, as well as advantages of using liquid membranes in laboratory studies. These concepts are necessary to understand fundamental principles of liquid membrane transport. Due to the multiple advantages of liquid membranes several studies present analytical applications of the transport through liquid membranes in separation or preconcentration processes of metallic cations and some organic compounds, such as phenol and phenolic derivatives, organic acids, amino acids, carbohydrates, and drugs. This review presents coupled techniques such as separation through the liquid membrane coupled with flow injection analysis.

The multidimensional nature of HIV stigma: evidence from Mozambique.

PubMed

Carrasco, Maria A; Arias, Rosario; Figueroa, Maria E

2017-03-01

HIV stigma continues to be a major challenge to addressing HIV/AIDS in various countries in sub-Saharan Africa, including Mozambique. This paper explores the multidimensional nature of HIV stigma through the thematic analysis of five qualitative studies conducted in high HIV prevalence provinces in Mozambique between 2009 and 2012. These studies included 23 interviews with people living with HIV (PLHIV) (10 women and 13 men); 6 focus groups with 32 peer educators (24 women and 8 men) working for community-based organisations (CBOs) providing services to PLHIV; 17 focus groups with community members (72 men and 70 women); 6 interviews (4 women and 2 men) with people who had family members living with HIV/AIDS; 24 focus groups (12 with men and 12 with women) and 6 interviews with couples. Our findings indicate that HIV stigma is a barrier to HIV testing and counselling, status disclosure, partner notification, and antiretroviral therapy (ART) access and adherence, and that moral stigma seems to be more common than physical stigma. Additionally, the findings highlight that HIV stigma is a dynamic social process that is conceptualised as being tied to personal responsibility. To effectively diminish HIV stigma in Mozambique, future interventions should address moral stigma and re-conceptualise HIV as a chronic disease.

Trends in data processing of comprehensive two-dimensional chromatography: state of the art.

PubMed

Matos, João T V; Duarte, Regina M B O; Duarte, Armando C

2012-12-01

The operation of advanced chromatographic systems, namely comprehensive two-dimensional (2D) chromatography coupled to multidimensional detectors, allows achieving a great deal of data that need special care to be processed in order to characterize and quantify as much as possible the analytes under study. The aim of this review is to identify the main trends, research needs and gaps on the techniques for data processing of multidimensional data sets obtained from comprehensive 2D chromatography. The following topics have been identified as the most promising for new developments in the near future: data acquisition and handling, peak detection and quantification, measurement of overlapping of 2D peaks, and data analysis software for 2D chromatography. The rational supporting most of the data processing techniques is based on the generalization of one-dimensional (1D) chromatography although algorithms, such as the inverted watershed algorithm, use the 2D chromatographic data as such. However, for processing more complex N-way data there is a need for using more sophisticated techniques. Apart from using other concepts from 1D chromatography, which have not been tested for 2D chromatography, there is still room for new improvements and developments in algorithms and software for dealing with 2D comprehensive chromatographic data. Copyright © 2012 Elsevier B.V. All rights reserved.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers.

PubMed

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers

NASA Astrophysics Data System (ADS)

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Strong Coupling and Entanglement of Quantum Emitters Embedded in a Nanoantenna-Enhanced Plasmonic Cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hensen, Matthias; Heilpern, Tal; Gray, Stephen K.

Establishing strong coupling between spatially separated and thus selectively addressable quantum emitters is a key ingredient to complex quantum optical schemes in future technologies. Insofar as many plasmonic nanostructures are concerned, however, the energy transfer and mutual interaction strength between distant quantum emitters can fail to provide strong coupling. Here, based on mode hybridization, the longevity and waveguide character of an elliptical plasmon cavity are combined with intense and highly localized field modes of suitably designed nanoantennas. Based on FDTD simulations a quantum emitter-plasmon coupling strength hg = 16.7 meV is reached while simultaneously keeping a small plasmon resonance linemore » width h gamma(s) = 33 meV. This facilitates strong coupling, and quantum dynamical simulations reveal an oscillatory exchange of excited state population arid a notable degree of entanglement between the quantum emitters spatially separated by 1.8 mu m, i.e., about twice the operating wavelength.« less

Trends in mass spectrometry instrumentation for proteomics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Richard D.

2002-12-01

Mass spectrometry has become a primary tool for proteomics due to its capabilities for rapid and sensitive protein identification and quantitation. It is now possible to identify thousands of proteins from microgram sample quantities in a single day and to quantify relative protein abundances. However, the needs for increased capabilities for proteome measurements are immense and are now driving both new strategies and instrument advances. These developments include those based on integration with multi-dimensional liquid separations and high accuracy mass measurements, and promise more than order of magnitude improvements in sensitivity, dynamic range, and throughput for proteomic analyses in themore » near future.« less

What History Tells Us about the Distinct Nature of Chemistry.

PubMed

Chang, Hasok

2017-11-01

Attention to the history of chemistry can help us recognise the characteristics of chemistry that have helped to maintain it as a separate scientific discipline with a unique identity. Three such features are highlighted in this paper. First, chemistry has maintained a distinct type of theoretical thinking, independent from that of physics even in the era of quantum chemistry. Second, chemical research has always been shaped by its ineliminable practical relevance and usefulness. Third, the lived experience of chemistry, spanning the laboratory, the classroom and everyday life, is distinctive in its multidimensional sensuousness. Furthermore, I argue that the combination of these three features makes chemistry an exemplary science.

Quality by Design: Multidimensional exploration of the design space in high performance liquid chromatography method development for better robustness before validation.

PubMed

Monks, K; Molnár, I; Rieger, H-J; Bogáti, B; Szabó, E

2012-04-06

Robust HPLC separations lead to fewer analysis failures and better method transfer as well as providing an assurance of quality. This work presents the systematic development of an optimal, robust, fast UHPLC method for the simultaneous assay of two APIs of an eye drop sample and their impurities, in accordance with Quality by Design principles. Chromatography software is employed to effectively generate design spaces (Method Operable Design Regions), which are subsequently employed to determine the final method conditions and to evaluate robustness prior to validation. Copyright © 2011 Elsevier B.V. All rights reserved.

On the Need for Multidimensional Stirling Simulations

NASA Technical Reports Server (NTRS)

Dyson, Rodger W.; Wilson, Scott D.; Tew, Roy C.; Demko, Rikako

2005-01-01

Given the cost and complication of simulating Stirling convertors, do we really need multidimensional modeling when one-dimensional capabilities exist? This paper provides a comprehensive description of when and why multidimensional simulation is needed.

Multidimensional Scaling in the Poincare Disk

DTIC Science & Technology

2011-05-01

REPORT Multidimensional Scaling in the Poincare Dis 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: Multidimensional scaling (MDS) is a class of projective...DATES COVERED (From - To) Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - Multidimensional Scaling in the Poincare Dis Report Title... plane . Our construction is based on an approximate hyperbolic line search and exempli?es some of the particulars that need to be addressed when

A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction

PubMed Central

Gao, Yang; Li, Hongsheng; Huang, Libin; Sun, Hui

2017-01-01

This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope’s modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity. PMID:28468288

Preliminary SP-100/Stirling Heat Exchanger Designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brain; Dunn, Pat

1994-07-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor(SSPC)was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-12-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Technical Reports Server (NTRS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-01-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Gas-liquid separator and method of operation

DOEpatents

Soloveichik, Grigorii Lev [Latham, NY; Whitt, David Brandon [Albany, NY

2009-07-14

A system for gas-liquid separation in electrolysis processes is provided. The system includes a first compartment having a liquid carrier including a first gas therein and a second compartment having the liquid carrier including a second gas therein. The system also includes a gas-liquid separator fluidically coupled to the first and second compartments for separating the liquid carrier from the first and second gases.

Directional radiation pattern in structural-acoustic coupled system

NASA Astrophysics Data System (ADS)

Seo, Hee-Seon; Kim, Yang-Hann

2005-07-01

In this paper we demonstrate the possibility of designing a radiator using structural-acoustic interaction by predicting the pressure distribution and radiation pattern of a structural-acoustic coupling system that is composed by a wall and two spaces. If a wall separates spaces, then the wall's role in transporting the acoustic characteristics of the spaces is important. The spaces can be categorized as bounded finite space and unbounded infinite space. The wall considered in this study composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. This rather hypothetical circumstance is selected to study the general coupling problem between the finite and infinite acoustic domains. We developed an equation that predicts the energy distribution and energy flow in the two spaces separated by a wall, and its computational examples are presented. Three typical radiation patterns that include steered, focused, and omnidirected are presented. A designed radiation pattern is also presented by using the optimal design algorithm.

Purification of α-glucosidase from mouse intestine by countercurrent chromatography coupled with a reverse micelle solvent system.

PubMed

He, Kai; Zou, Zongyao; Hu, Yinran; Yang, Yong; Xiao, Yubo; Gao, Pincao; Li, Xuegang; Ye, Xiaoli

2016-02-01

Countercurrent chromatography coupled with a reverse micelle solvent was applied to separate α-glucosidase, which is stable at pH 6.0-8.8, 15-50°C. The separation conditions are as follows: stationary phase: pH 4.0 Tris-HCl buffer phase containing 50 mM Tris-HCl and 50 mM KCl; mobile phase A: isooctane containing 50 mM anionic surfactant sodium di(2-ethylhexyl)sulfosuccinate; mobile phase B: 50 mM Tris-HCl buffer containing 500 mM KCl (pH 8.0); In total, 25 mL (23.9 mg) crude enzyme was injected through the injection valve, the enzymatic reaction and sodium dodecylsulfate polyacrylamide gel electrophoresis results imply that the activity of purified α-glucosidase is 6.63-fold higher than that of the crude enzyme. Therefore, countercurrent chromatography coupled with a reverse micelle solvent is capable for protein separation and enrichment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solving coupled groundwater flow systems using a Jacobian Free Newton Krylov method

NASA Astrophysics Data System (ADS)

Mehl, S.

2012-12-01

Jacobian Free Newton Kyrlov (JFNK) methods can have several advantages for simulating coupled groundwater flow processes versus conventional methods. Conventional methods are defined here as those based on an iterative coupling (rather than a direct coupling) and/or that use Picard iteration rather than Newton iteration. In an iterative coupling, the systems are solved separately, coupling information is updated and exchanged between the systems, and the systems are re-solved, etc., until convergence is achieved. Trusted simulators, such as Modflow, are based on these conventional methods of coupling and work well in many cases. An advantage of the JFNK method is that it only requires calculation of the residual vector of the system of equations and thus can make use of existing simulators regardless of how the equations are formulated. This opens the possibility of coupling different process models via augmentation of a residual vector by each separate process, which often requires substantially fewer changes to the existing source code than if the processes were directly coupled. However, appropriate perturbation sizes need to be determined for accurate approximations of the Frechet derivative, which is not always straightforward. Furthermore, preconditioning is necessary for reasonable convergence of the linear solution required at each Kyrlov iteration. Existing preconditioners can be used and applied separately to each process which maximizes use of existing code and robust preconditioners. In this work, iteratively coupled parent-child local grid refinement models of groundwater flow and groundwater flow models with nonlinear exchanges to streams are used to demonstrate the utility of the JFNK approach for Modflow models. Use of incomplete Cholesky preconditioners with various levels of fill are examined on a suite of nonlinear and linear models to analyze the effect of the preconditioner. Comparisons of convergence and computer simulation time are made using conventional iteratively coupled methods and those based on Picard iteration to those formulated with JFNK to gain insights on the types of nonlinearities and system features that make one approach advantageous. Results indicate that nonlinearities associated with stream/aquifer exchanges are more problematic than those resulting from unconfined flow.

Scaling Laws for the Multidimensional Burgers Equation with Quadratic External Potential

NASA Astrophysics Data System (ADS)

Leonenko, N. N.; Ruiz-Medina, M. D.

2006-07-01

The reordering of the multidimensional exponential quadratic operator in coordinate-momentum space (see X. Wang, C.H. Oh and L.C. Kwek (1998). J. Phys. A.: Math. Gen. 31:4329-4336) is applied to derive an explicit formulation of the solution to the multidimensional heat equation with quadratic external potential and random initial conditions. The solution to the multidimensional Burgers equation with quadratic external potential under Gaussian strongly dependent scenarios is also obtained via the Hopf-Cole transformation. The limiting distributions of scaling solutions to the multidimensional heat and Burgers equations with quadratic external potential are then obtained under such scenarios.

Models of multidimensional discrete distribution of probabilities of random variables in information systems

NASA Astrophysics Data System (ADS)

Gromov, Yu Yu; Minin, Yu V.; Ivanova, O. G.; Morozova, O. N.

2018-03-01

Multidimensional discrete distributions of probabilities of independent random values were received. Their one-dimensional distribution is widely used in probability theory. Producing functions of those multidimensional distributions were also received.

A New Time-varying Concept of Risk in a Changing Climate.

PubMed

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P

2016-10-20

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

Search for lepton flavor violation in upsilon decays.

PubMed

Love, W; Savinov, V; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Horwitz, N; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ecklund, K M

2008-11-14

In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Upsilon(nS)-->mutau (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay nu_{tau}nu[over ]_{e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Rapid 3D NMR using the filter diagonalization method: application to oligosaccharides derivatized with 13C-labeled acetyl groups

NASA Astrophysics Data System (ADS)

Armstrong, Geoffrey S.; Cano, Kristin E.; Mandelshtam, Vladimir A.; Shaka, A. J.; Bendiak, Brad

2004-09-01

Rapid 3D NMR spectroscopy of oligosaccharides having isotopically labeled acetyl "isotags" was made possible with high resolution in the indirect dimensions using the filter diagonalization method (FDM). A pulse sequence was designed for the optimal correlation of acetyl methyl protons, methyl carbons, and carbonyl carbons. The multi-dimensional nature of the FDM, coupled with the advantages of constant-time evolution periods, resulted in marked improvements over Fourier transform (FT) and mirror-image linear prediction (MI-LP) processing methods. The three methods were directly compared using identical data sets. A highly resolved 3D spectrum was achieved with the FDM using a very short experimental time (28 min).

Rapid 3D NMR using the filter diagonalization method: application to oligosaccharides derivatized with 13C-labeled acetyl groups.

PubMed

Armstrong, Geoffrey S; Cano, Kristin E; Mandelshtam, Vladimir A; Shaka, A J; Bendiak, Brad

2004-09-01

Rapid 3D NMR spectroscopy of oligosaccharides having isotopically labeled acetyl "isotags" was made possible with high resolution in the indirect dimensions using the filter diagonalization method (FDM). A pulse sequence was designed for the optimal correlation of acetyl methyl protons, methyl carbons, and carbonyl carbons. The multi-dimensional nature of the FDM, coupled with the advantages of constant-time evolution periods, resulted in marked improvements over Fourier transform (FT) and mirror-image linear prediction (MI-LP) processing methods. The three methods were directly compared using identical data sets. A highly resolved 3D spectrum was achieved with the FDM using a very short experimental time (28 min).

Glyceraldehyde and glycolaldehyde in interstellar ice analogues and the role of aldehydes in cosmochemical evolution

NASA Astrophysics Data System (ADS)

Meierhenrich, U.; de Marcellus, P.; Meinert, C.; Myrgorodska, I.; Nahon, L.; Buhse, T.; d'Hendecourt, L.

2015-10-01

Our understanding of the molecular origin of life is based on amino acids, ribose, and nucleobases that - after their selection by prebiotic processes - initiated the evolutionary assembly of catalytic and informational polymers, being proteins and ribonucleic acids. Following previous amino acid identifications in the room-temperature residues of simulated circumstellar/interstellar ices [1,2] we have searched for a different family of molecules of potential prebiotic interest. Using multidimensional gas chromatography coupled to time-of-flight mass spectrometry, we have detected ten aldehydes, including the sugar-related glycolaldehyde and glyceraldehyde - two species considered as key prebiotic intermediates in the first steps toward the synthesis of ribonucleotides in a planetary environment.

Search for Lepton Flavor Violation in Upsilon Decays

NASA Astrophysics Data System (ADS)

Love, W.; Savinov, V.; Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J.; Huang, G. S.; Miller, D. H.; Pavlunin, V.; Sanghi, B.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Horwitz, N.; Khalil, S.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Asner, D. M.; Edwards, K. W.; Naik, P.; Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Berkelman, K.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Pivarski, J.; Riley, D.; Ryd, A.; Sadoff, A. J.; Schwarthoff, H.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Cawlfield, C.; Eisenstein, B. I.; Karliner, I.; Kim, D.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Smith, A.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Ecklund, K. M.

2008-11-01

In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Υ(nS)→μτ (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the τ lepton using its leptonic decay ντν¯ee and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Υ mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Two-dimensional fourier transform spectrometer

DOEpatents

DeFlores, Lauren; Tokmakoff, Andrei

2016-10-25

The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

Two-dimensional fourier transform spectrometer

DOEpatents

DeFlores, Lauren; Tokmakoff, Andrei

2013-09-03

The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

Induced vacuum energy-momentum tensor in the background of a cosmic string

NASA Astrophysics Data System (ADS)

Sitenko, Yu A.; Vlasii, N. D.

2012-05-01

A massive scalar field is quantized in the background of a cosmic string which is generalized to a static flux-carrying codimension-2 brane in the locally flat multidimensional spacetime. We find that the finite energy-momentum tensor is induced in the vacuum. The dependence of the tensor components on the brane flux and tension, as well as on the coupling to the spacetime curvature scalar, is comprehensively analyzed. The tensor components are holomorphic functions of space dimension, decreasing exponentially with the distance from the brane. The case of the massless quantized scalar field is also considered, and the relevance of Bernoulli’s polynomials of even order for this case is discussed.

Ultrafast coherence transfer in DNA-templated silver nanoclusters

PubMed Central

Thyrhaug, Erling; Bogh, Sidsel Ammitzbøll; Carro-Temboury, Miguel R; Madsen, Charlotte Stahl; Vosch, Tom; Zigmantas, Donatas

2017-01-01

DNA-templated silver nanoclusters of a few tens of atoms or less have come into prominence over the last several years due to very strong absorption and efficient emission. Applications in microscopy and sensing have already been realized, however little is known about the excited-state structure and dynamics in these clusters. Here we report on a multidimensional spectroscopy investigation of the energy-level structure and the early-time relaxation cascade, which eventually results in the population of an emitting state. We find that the ultrafast intramolecular relaxation is strongly coupled to a specific vibrational mode, resulting in the concerted transfer of population and coherence between excited states on a sub-100 fs timescale. PMID:28548085

Mass media influence spreading in social networks with community structure

NASA Astrophysics Data System (ADS)

Candia, Julián; Mazzitello, Karina I.

2008-07-01

We study an extension of Axelrod's model for social influence, in which cultural drift is represented as random perturbations, while mass media are introduced by means of an external field. In this scenario, we investigate how the modular structure of social networks affects the propagation of mass media messages across a society. The community structure of social networks is represented by coupled random networks, in which two random graphs are connected by intercommunity links. Considering inhomogeneous mass media fields, we study the conditions for successful message spreading and find a novel phase diagram in the multidimensional parameter space. These findings show that social modularity effects are of paramount importance for designing successful, cost-effective advertising campaigns.

Hybridation of different chiral separation techniques with ICP-MS detection for the separation and determination of selenomethionine enantiomers: chiral speciation of selenized yeast.

PubMed

Méndez, S P; González, E B; Sanz-Medel, A

2001-05-01

Enantioseparation and determination of selenomethionine enantiomers in selenized yeast was investigated using chiral separation techniques based on different principles, coupled on-line to inductively coupled plasma mass spectrometry (ICP-MS) for selenium-specific detection. High performance liquid chromatography (HPLC) on a beta-cyclodestrin (beta-CD) column, cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC), gas chromatography (GC) on a Chirasil-L-Val column, and HPLC on a Chirobiotic T column have been investigated as the chiral separation techniques. For HPLC separation on the beta-CD column, and also for CD-MEKC, selenomethionine enantiomers were derivatized with NDA/CN(-). For chiral separation by GC, selenomethionine enantiomers were converted into their N-trifluoroacetyl (TFA)-O-alkyl esters. The developed hybridation methodologies are compared with respect to enantioselectivity, sensitivity and analysis time. The usefulness of the best-suited method [HPLC (Chirobiotic T)-ICP-MS] was demonstrated by its application to the successful chiral speciation of selenium and D-and L-selenomethionine content determination in selenized yeast. Copyright 2001 John Wiley & Sons, Ltd.

Separation of Opiate Isomers Using Electrospray Ionization and Paper Spray Coupled to High-Field Asymmetric Waveform Ion Mobility Spectrometry

NASA Astrophysics Data System (ADS)

Manicke, Nicholas E.; Belford, Michael

2015-05-01

One limitation in the growing field of ambient or direct analysis methods is reduced selectivity caused by the elimination of chromatographic separations prior to mass spectrometric analysis. We explored the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS), an ambient pressure ion mobility technique, to separate the closely related opiate isomers of morphine, hydromorphone, and norcodeine. These isomers cannot be distinguished by tandem mass spectrometry. Separation prior to MS analysis is, therefore, required to distinguish these compounds, which are important in clinical chemistry and toxicology. FAIMS was coupled to a triple quadrupole mass spectrometer, and ionization was performed using either a pneumatically assisted heated electrospray ionization source (H-ESI) or paper spray, a direct analysis method that has been applied to the direct analysis of dried blood spots and other complex samples. We found that FAIMS was capable of separating the three opiate structural isomers using both H-ESI and paper spray as the ionization source.

Chromatographic Techniques for Rare Earth Elements Analysis

NASA Astrophysics Data System (ADS)

Chen, Beibei; He, Man; Zhang, Huashan; Jiang, Zucheng; Hu, Bin

2017-04-01

The present capability of rare earth element (REE) analysis has been achieved by the development of two instrumental techniques. The efficiency of spectroscopic methods was extraordinarily improved for the detection and determination of REE traces in various materials. On the other hand, the determination of REEs very often depends on the preconcentration and separation of REEs, and chromatographic techniques are very powerful tools for the separation of REEs. By coupling with sensitive detectors, many ambitious analytical tasks can be fulfilled. Liquid chromatography is the most widely used technique. Different combinations of stationary phases and mobile phases could be used in ion exchange chromatography, ion chromatography, ion-pair reverse-phase chromatography and some other techniques. The application of gas chromatography is limited because only volatile compounds of REEs can be separated. Thin-layer and paper chromatography are techniques that cannot be directly coupled with suitable detectors, which limit their applications. For special demands, separations can be performed by capillary electrophoresis, which has very high separation efficiency.

Use of microextraction by packed sorbent directly coupled to an electron ionization single quadrupole mass spectrometer as an alternative for non-separative determinations.

PubMed

Casas Ferreira, Ana María; Moreno Cordero, Bernardo; Pérez Pavón, José Luis

2017-02-01

Sometimes it is not necessary to separate the individual compounds of a sample to resolve an analytical problem, it is enough to obtain a signal profile of the sample formed by all the components integrating it. Within this strategy, electronic noses based on the direct coupling of a headspace sampler with a mass spectrometer (HS-MS) have been proposed. Nevertheless, this coupling is not suitable for the analysis of non-volatile compounds. In order to propose an alternative to HS-MS determinations for non-volatile compounds, here we present the first 'proof of concept' use of the direct coupling of microextraction by packed sorbents (MEPS) to a mass spectrometer device using an electron ionization (EI) and a single quadrupole as ionization source and analyzer, respectively. As target compounds, a set of analytes with different physic-chemical properties were evaluated (2-ethyl-1-hexanol, styrene, 2-heptanone, among others). The use of MEPS extraction present many advantages, such as it is fast, simple, easy to automate and requires small volumes of sample and organic solvents. Moreover, MEPS cartridges are re-usable as samples can be extracted more than 100 times using the same syringe. In order to introduce into the system all the elution volume from the MEPS extraction, a programmable temperature vaporizer (PTV) is proposed as the injector device. Results obtained with the proposed methodology (MEPS-PTV/MS) were compared with the ones obtained based on the separative scheme, i.e. using gas chromatography separation (MEPS-PTV-GC/MS), and both methods provided similar results. Limits of detection were found to be between 3.26 and 146.6μgL -1 in the non-separative scheme and between 0.02 and 1.72μgL -1 when the separative methodology was used. Repeatability and reproducibility were evaluated with values below 17% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

Sign of coupling in barrier-separated Bose-Einstein condensates and stability of double-ring systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brand, J.; Haigh, T. J.; Zuelicke, U.

We revisit recent claims about the instability of nonrotating tunnel coupled annular Bose-Einstein condensates leading to the emergence of angular momentum Josephson oscillation [Phys. Rev. Lett. 98, 050401 (2007)]. It was predicted that all stationary states with uniform density become unstable in certain parameter regimes. By careful analysis, we arrive at a different conclusion. We show that there is a stable nonrotating and uniform ground state for any value of the tunnel coupling and repulsive interactions. The instability of an excited state with {pi} phase difference between the condensates can be interpreted in terms of the familiar snake instability. Wemore » further discuss the sign of the tunnel coupling through a separating barrier, which carries significance for the nature of the stationary states. It is found to always be negative for physical reasons.« less

Multidimensional Knowledge Structures.

ERIC Educational Resources Information Center

Schuh, Kathy L.

Multidimensional knowledge structures, described from a constructivist perspective and aligned with the "Mind as Rhizome" metaphor, provide support for constructivist learning strategies. This qualitative study was conducted to seek empirical support for a description of multidimensional knowledge structures, focusing on the…

Multidimensional quantum entanglement with large-scale integrated optics.

PubMed

Wang, Jianwei; Paesani, Stefano; Ding, Yunhong; Santagati, Raffaele; Skrzypczyk, Paul; Salavrakos, Alexia; Tura, Jordi; Augusiak, Remigiusz; Mančinska, Laura; Bacco, Davide; Bonneau, Damien; Silverstone, Joshua W; Gong, Qihuang; Acín, Antonio; Rottwitt, Karsten; Oxenløwe, Leif K; O'Brien, Jeremy L; Laing, Anthony; Thompson, Mark G

2018-04-20

The ability to control multidimensional quantum systems is central to the development of advanced quantum technologies. We demonstrate a multidimensional integrated quantum photonic platform able to generate, control, and analyze high-dimensional entanglement. A programmable bipartite entangled system is realized with dimensions up to 15 × 15 on a large-scale silicon photonics quantum circuit. The device integrates more than 550 photonic components on a single chip, including 16 identical photon-pair sources. We verify the high precision, generality, and controllability of our multidimensional technology, and further exploit these abilities to demonstrate previously unexplored quantum applications, such as quantum randomness expansion and self-testing on multidimensional states. Our work provides an experimental platform for the development of multidimensional quantum technologies. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Systems analysis of singly and multiply O-glycosylated peptides in the human serum glycoproteome via EThcD and HCD mass spectrometry.

PubMed

Zhang, Yong; Xie, Xinfang; Zhao, Xinyuan; Tian, Fang; Lv, Jicheng; Ying, Wantao; Qian, Xiaohong

2018-01-06

Human serum has been intensively studied to identify biomarkers via global proteomic analysis. The altered O-glycoproteome is associated with human pathological state including cancer, inflammatory and degenerative diseases and is an attractive source of disease biomarkers. Because of the microheterogeneity and macroheterogeneity of O-glycosylation, site-specific O-glycosylation analysis in human serum is still challenging. Here, we developed a systematic strategy that combined multiple enzyme digestion, multidimensional separation for sample preparation and high-resolution tandem MS with Byonic software for intact O-glycopeptide characterization. We demonstrated that multiple enzyme digestion or multidimensional separation can make sample preparation more efficient and that EThcD is not only suitable for the identification of singly O-glycosylated peptides (50.3%) but also doubly (21.2%) and triply (28.5%) O-glycosylated peptides. Totally, with the strict scoring criteria, 499 non-redundant intact O-glycopeptides, 173 O-glycosylation sites and 6 types of O-glycans originating from 49 O-glycoprotein groups were identified in human serum, including 121 novel O-glycosylation sites. Currently, this is the largest data set of site-specific native O-glycoproteome from human serum samples. We expect that the strategies developed by this study will facilitate in-depth analyses of native O-glycoproteomes in human serum and provide opportunities to understand the functional roles of protein O-glycosylation in human health and diseases. The altered O-glycoproteome is associated with human pathological state and is an attractive source of disease biomarkers. However, site-specific O-glycosylation analysis is challenging because of the microheterogeneity (different glycoforms attached to one glycosylation site) and macroheterogeneity (site occupancy) of O-glycosylation. In this work, we developed a systematic strategy for intact O-glycopeptide characterization. This study took advantage of the inherent properties of the new fragmentation method called EThcD, which provides more complete fragmentation information about O-glycosylated peptides and a more confident site localization of O-glycans than collision-induced dissociation (HCD). We demonstrated that multiple enzyme digestion or multidimensional separation can make sample preparation more efficient and that EThcD was not only suitable for the identification of singly O-glycosylated peptides (50.3%) but also doubly (21.2%) and triply (28.5%) O-glycosylated peptides. Finally, we got a largest data set of site-specific native O-glycoproteome from human serum samples. Furthermore, quantitative analysis of intact O-glycopeptides from the serum samples of IgA nephropathy (IgAN) patients and healthy donors was performed, and the results showed the potential of the strategy to discover O-glycosylation biomarkers. We expect that the strategies developed by this study will facilitate in-depth analyses of native O-glycoproteomes in human serum and lead to exciting opportunities to understand the functional roles of protein O-glycosylation in human health and diseases. Copyright © 2017. Published by Elsevier B.V.

Recent development in mass spectrometry and its hyphenated techniques for the analysis of medicinal plants.

PubMed

Zhu, Ming-Zhi; Chen, Gui-Lin; Wu, Jian-Lin; Li, Na; Liu, Zhong-Hua; Guo, Ming-Quan

2018-04-23

Medicinal plants are gaining increasing attention worldwide due to their empirical therapeutic efficacy and being a huge natural compound pool for new drug discovery and development. The efficacy, safety and quality of medicinal plants are the main concerns, which are highly dependent on the comprehensive analysis of chemical components in the medicinal plants. With the advances in mass spectrometry (MS) techniques, comprehensive analysis and fast identification of complex phytochemical components have become feasible, and may meet the needs, for the analysis of medicinal plants. Our aim is to provide an overview on the latest developments in MS and its hyphenated technique and their applications for the comprehensive analysis of medicinal plants. Application of various MS and its hyphenated techniques for the analysis of medicinal plants, including but not limited to one-dimensional chromatography, multiple-dimensional chromatography coupled to MS, ambient ionisation MS, and mass spectral database, have been reviewed and compared in this work. Recent advancs in MS and its hyphenated techniques have made MS one of the most powerful tools for the analysis of complex extracts from medicinal plants due to its excellent separation and identification ability, high sensitivity and resolution, and wide detection dynamic range. To achieve high-throughput or multi-dimensional analysis of medicinal plants, the state-of-the-art MS and its hyphenated techniques have played, and will continue to play a great role in being the major platform for their further research in order to obtain insight into both their empirical therapeutic efficacy and quality control. Copyright © 2018 John Wiley & Sons, Ltd.

Maximizing the significance in Higgs boson pair analyses [Mad-Maximized Higgs Pair Analyses

DOE PAGES

Kling, Felix; Plehn, Tilman; Schichtel, Peter

2017-02-22

Here, we study Higgs pair production with a subsequent decay to a pair of photons and a pair of bottoms at the LHC. We use the log-likelihood ratio to identify the kinematic regions which either allow us to separate the di-Higgs signal from backgrounds or to determine the Higgs self-coupling. We find that both regions are separate enough to ensure that details of the background modeling will not affect the determination of the self-coupling. Assuming dominant statistical uncertainties we determine the best precision with which the Higgs self-coupling can be probed in this channel. We finally comment on the samemore » questions at a future 100 TeV collider.« less

Maximizing the significance in Higgs boson pair analyses [Mad-Maximized Higgs Pair Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kling, Felix; Plehn, Tilman; Schichtel, Peter

Here, we study Higgs pair production with a subsequent decay to a pair of photons and a pair of bottoms at the LHC. We use the log-likelihood ratio to identify the kinematic regions which either allow us to separate the di-Higgs signal from backgrounds or to determine the Higgs self-coupling. We find that both regions are separate enough to ensure that details of the background modeling will not affect the determination of the self-coupling. Assuming dominant statistical uncertainties we determine the best precision with which the Higgs self-coupling can be probed in this channel. We finally comment on the samemore » questions at a future 100 TeV collider.« less

Quantized orbits in weakly coupled Belousov-Zhabotinsky reactors

NASA Astrophysics Data System (ADS)

Weiss, S.; Deegan, R. D.

2015-06-01

Using numerical and experimental tools, we study the motion of two coupled spiral cores in a light-sensitive variant of the Belousov-Zhabotinsky reaction. Each core resides on a separate two-dimensional domain, and is coupled to the other by light. When both spirals have the same sense of rotation, the cores are attracted to a circular trajectory with a diameter quantized in integer units of the spiral wavelength λ. When the spirals have opposite senses of rotation, the cores are attracted towards different but parallel straight trajectories, separated by an integer multiple of λ/2. We present a model that explains this behavior as the result of a spiral wavefront-core interaction that produces a deterministic displacement of the core and a retardation of its phase.

Experience of gastric cancer survivors and their spouses in Korea: secondary analysis.

PubMed

Yi, Myungsun; Kahn, David

2004-06-01

The purpose of this study was to explore the experiences of gastric cancer couples in Korea and to generate a substantive theory integrating the experiences of gastric cancer survivors and their spouses as a whole. The specific aims of this study were to explore major problems gastric cancer couples faced and how they resolved these problems, focusing on inter-relational dynamics within the couples and on similarities and differences between the couples. This was a secondary analysis study using grounded theory techniques. The study used the data of 11 married couples which was collected from in-depth interviews from two primary studies. The unit of analysis was dyads of gastric cancer survivors and their spouses. The basic social psychological process that emerged from the analysis was "taking charge of their health." Major categories involved in this process were identified as 1) adjusting to new diets, 2) reinforcing physical strength, 3) seeking information, 4) strengthening Ki, 5) lowering life-expectations, and 6) going their separate ways. These six categories represent major strategies in overcoming critical problems that occurred in day-to-day experiences. In terms of the process, the first five categories characterize the earlier stage of the process of "taking charge of their health," while "going their separate ways" indicates the later stage and also the beginning of their separate ways: "pursuing spiritual life" for the survivors, and "preparing for the future" for the spouses. The results of this study will help design family care for the people with gastric cancer by providing in-depth understanding and insight on the lives of gastric cancer couples.

Comparison of originator and biosimilar therapeutic monoclonal antibodies using comprehensive two-dimensional liquid chromatography coupled with time-of-flight mass spectrometry.

PubMed

Sorensen, Matthew; Harmes, David C; Stoll, Dwight R; Staples, Gregory O; Fekete, Szabolcs; Guillarme, Davy; Beck, Alain

2016-10-01

As research, development, and manufacturing of biosimilar protein therapeutics proliferates, there is great interest in the continued development of a portfolio of complementary analytical methods that can be used to efficiently and effectively characterize biosimilar candidate materials relative to the respective reference (i.e., originator) molecule. Liquid phase separation techniques such as liquid chromatography and capillary electrophoresis are powerful tools that can provide both qualitative and quantitative information about similarities and differences between reference and biosimilar materials, especially when coupled with mass spectrometry. However, the inherent complexity of these protein materials challenges even the most modern one-dimensional (1D) separation methods. Two-dimensional (2D) separations present a number of potential advantages over 1D methods, including increased peak capacity, 2D peak patterns that can facilitate unknown identification, and improvement in the compatibility of some separation methods with mass spectrometry. In this study, we demonstrate the use of comprehensive 2D-LC separations involving cation-exchange (CEX) and reversed-phase (RP) separations in the first and second dimensions to compare 3 reference/biosimilar pairs of monoclonal antibodies (cetuximab, trastuzumab and infliximab) that cover a range of similarity/disimilarity in a middle-up approach. The second dimension RP separations are coupled to time-of-flight mass spectrometry, which enables direct identification of features in the chromatograms obtained from mAbs digested with the IdeS enzyme, or digestion with IdeS followed by reduction with dithiothreitol. As many as 23 chemically unique mAb fragments were detected in a single sample. Our results demonstrate that these rich datasets enable facile assesment of the degree of similarity between reference and biosimilar materials.

Risk assessment and adaptive runoff utilization in water resource system considering the complex relationship among water supply, electricity generation and environment

NASA Astrophysics Data System (ADS)

Zhou, J.; Zeng, X.; Mo, L.; Chen, L.; Jiang, Z.; Feng, Z.; Yuan, L.; He, Z.

2017-12-01

Generally, the adaptive utilization and regulation of runoff in the source region of China's southwest rivers is classified as a typical multi-objective collaborative optimization problem. There are grim competitions and incidence relation in the subsystems of water supply, electricity generation and environment, which leads to a series of complex problems represented by hydrological process variation, blocked electricity output and water environment risk. Mathematically, the difficulties of multi-objective collaborative optimization focus on the description of reciprocal relationships and the establishment of evolving model of adaptive systems. Thus, based on the theory of complex systems science, this project tries to carry out the research from the following aspects: the changing trend of coupled water resource, the covariant factor and driving mechanism, the dynamic evolution law of mutual feedback dynamic process in the supply-generation-environment coupled system, the environmental response and influence mechanism of coupled mutual feedback water resource system, the relationship between leading risk factor and multiple risk based on evolutionary stability and dynamic balance, the transfer mechanism of multiple risk response with the variation of the leading risk factor, the multidimensional coupled feedback system of multiple risk assessment index system and optimized decision theory. Based on the above-mentioned research results, the dynamic method balancing the efficiency of multiple objectives in the coupled feedback system and optimized regulation model of water resources is proposed, and the adaptive scheduling mode considering the internal characteristics and external response of coupled mutual feedback system of water resource is established. In this way, the project can make a contribution to the optimal scheduling theory and methodology of water resource management under uncertainty in the source region of Southwest River.

A novel technology coupling extraction and foam fractionation for separating the total saponins from Achyranthes bidentata.

PubMed

Ding, Linlin; Wang, Yanji; Wu, Zhaoliang; Liu, Wei; Li, Rui; Wang, Yanyan

2016-10-02

A novel technology coupling extraction and foam fractionation was developed for separating the total saponins from Achyranthes bidentata. In the developed technology, the powder of A. bidentata was loaded in a nylon filter cloth pocket with bore diameter of 180 µm. The pocket was fixed in the bulk liquid phase for continuously releasing saponins. Under the optimal conditions, the concentration and the extraction rate of the total saponins in the foamate by the developed technology were 73.5% and 416.2% higher than those by the traditional technology, respectively. The foamates obtained by the traditional technology and the developed technology were analyzed by ultraperformance liquid chromatography-mass spectrometry to determine their ingredients, and the results appeared that the developed technology exhibited a better performance for separating saponins than the traditional technology. The study is expected to develop a novel technology for cost effectively separating plant-derived materials with surface activity.

A chip for catching, separating, and transporting bio-particles with dielectrophoresis.

PubMed

Huang, Jung-Tang; Wang, Guo-Chen; Tseng, Kuang-Ming; Fang, Shiuh-Bin

2008-11-01

This study aims at developing a 3D device for catching, separating, and transporting bio-particles based on dielectrophoresis (DEP). Target particles can be simultaneously caught and transported using the negative DEP method. In non-uniform electric fields, the levitation height or complex permittivity of certain particle may be different from that of another and this property can facilitate separation of particles. We have designed and constructed a 3D device consisting of two layers of electrodes separated by a channel formed by 50 microm thick photoresist. The electrodes can operate effectively with 10-15 V and 5-7 MHz to catch all particles in the channel, and can move particles after switching the electric field to 5-15 V and 500-1,000 KHz. Hence, particles experienced coupling force of two different directional twDEP forces, and tallied with our estimation to move along the coupling direction.

Multidimensional Perfectionism and the Self

ERIC Educational Resources Information Center

Ward, Andrew M.; Ashby, Jeffrey S.

2008-01-01

This study examined multidimensional perfectionism and self-development. Two hundred seventy-one undergraduates completed a measure of multidimensional perfectionism and two Kohutian measures designed to measure aspects of self-development including social connectedness, social assurance, goal instability (idealization), and grandiosity. The…

Chemical space visualization: transforming multidimensional chemical spaces into similarity-based molecular networks.

PubMed

de la Vega de León, Antonio; Bajorath, Jürgen

2016-09-01

The concept of chemical space is of fundamental relevance for medicinal chemistry and chemical informatics. Multidimensional chemical space representations are coordinate-based. Chemical space networks (CSNs) have been introduced as a coordinate-free representation. A computational approach is presented for the transformation of multidimensional chemical space into CSNs. The design of transformation CSNs (TRANS-CSNs) is based upon a similarity function that directly reflects distance relationships in original multidimensional space. TRANS-CSNs provide an immediate visualization of coordinate-based chemical space and do not require the use of dimensionality reduction techniques. At low network density, TRANS-CSNs are readily interpretable and make it possible to evaluate structure-activity relationship information originating from multidimensional chemical space.

Multidimensional poverty and catastrophic health spending in the mountainous regions of Myanmar, Nepal and India.

PubMed

Mohanty, Sanjay K; Agrawal, Nand Kishor; Mahapatra, Bidhubhusan; Choudhury, Dhrupad; Tuladhar, Sabarnee; Holmgren, E Valdemar

2017-01-18

Economic burden to households due to out-of-pocket expenditure (OOPE) is large in many Asian countries. Though studies suggest increasing household poverty due to high OOPE in developing countries, studies on association of multidimensional poverty and household health spending is limited. This paper tests the hypothesis that the multidimensionally poor are more likely to incur catastrophic health spending cutting across countries. Data from the Poverty and Vulnerability Assessment (PVA) Survey carried out by the International Center for Integrated Mountain Development (ICIMOD) has been used in the analyses. The PVA survey was a comprehensive household survey that covered the mountainous regions of India, Nepal and Myanmar. A total of 2647 households from India, 2310 households in Nepal and 4290 households in Myanmar covered under the PVA survey. Poverty is measured in a multidimensional framework by including the dimensions of education, income and energy, water and sanitation using the Alkire and Foster method. Health shock is measured using the frequency of illness, family sickness and death of any family member in a reference period of one year. Catastrophic health expenditure is defined as 40% above the household's capacity to pay. Results suggest that about three-fifths of the population in Myanmar, two-fifths of the population in Nepal and one-third of the population in India are multidimensionally poor. About 47% of the multidimensionally poor in India had incurred catastrophic health spending compared to 35% of the multidimensionally non-poor and the pattern was similar in both Nepal and Myanmar. The odds of incurring catastrophic health spending was 56% more among the multidimensionally poor than among the multidimensionally non-poor [95% CI: 1.35-1.76]. While health shocks to households are consistently significant predictors of catastrophic health spending cutting across country of residence, the educational attainment of the head of the household is not significant. The multidimensionally poor in the poorer regions are more likely to face health shocks and are less likely to afford professional health services. Increasing government spending on health and increasing households' access to health insurance can reduce catastrophic health spending and multidimensional poverty.

Modelling of LOCA Tests with the BISON Fuel Performance Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williamson, Richard L; Pastore, Giovanni; Novascone, Stephen Rhead

2016-05-01

BISON is a modern finite-element based, multidimensional nuclear fuel performance code that is under development at Idaho National Laboratory (USA). Recent advances of BISON include the extension of the code to the analysis of LWR fuel rod behaviour during loss-of-coolant accidents (LOCAs). In this work, BISON models for the phenomena relevant to LWR cladding behaviour during LOCAs are described, followed by presentation of code results for the simulation of LOCA tests. Analysed experiments include separate effects tests of cladding ballooning and burst, as well as the Halden IFA-650.2 fuel rod test. Two-dimensional modelling of the experiments is performed, and calculationsmore » are compared to available experimental data. Comparisons include cladding burst pressure and temperature in separate effects tests, as well as the evolution of fuel rod inner pressure during ballooning and time to cladding burst. Furthermore, BISON three-dimensional simulations of separate effects tests are performed, which demonstrate the capability to reproduce the effect of azimuthal temperature variations in the cladding. The work has been carried out in the frame of the collaboration between Idaho National Laboratory and Halden Reactor Project, and the IAEA Coordinated Research Project FUMAC.« less

ERP denoising in multichannel EEG data using contrasts between signal and noise subspaces.

PubMed

Ivannikov, Andriy; Kalyakin, Igor; Hämäläinen, Jarmo; Leppänen, Paavo H T; Ristaniemi, Tapani; Lyytinen, Heikki; Kärkkäinen, Tommi

2009-06-15

In this paper, a new method intended for ERP denoising in multichannel EEG data is discussed. The denoising is done by separating ERP/noise subspaces in multidimensional EEG data by a linear transformation and the following dimension reduction by ignoring noise components during inverse transformation. The separation matrix is found based on the assumption that ERP sources are deterministic for all repetitions of the same type of stimulus within the experiment, while the other noise sources do not obey the determinancy property. A detailed derivation of the technique is given together with the analysis of the results of its application to a real high-density EEG data set. The interpretation of the results and the performance of the proposed method under conditions, when the basic assumptions are violated - e.g. the problem is underdetermined - are also discussed. Moreover, we study how the factors of the number of channels and trials used by the method influence the effectiveness of ERP/noise subspaces separation. In addition, we explore also the impact of different data resampling strategies on the performance of the considered algorithm. The results can help in determining the optimal parameters of the equipment/methods used to elicit and reliably estimate ERPs.

Transient Two-Dimensional Analysis of Side Load in Liquid Rocket Engine Nozzles

NASA Technical Reports Server (NTRS)

Wang, Ten-See

2004-01-01

Two-dimensional planar and axisymmetric numerical investigations on the nozzle start-up side load physics were performed. The objective of this study is to develop a computational methodology to identify nozzle side load physics using simplified two-dimensional geometries, in order to come up with a computational strategy to eventually predict the three-dimensional side loads. The computational methodology is based on a multidimensional, finite-volume, viscous, chemically reacting, unstructured-grid, and pressure-based computational fluid dynamics formulation, and a transient inlet condition based on an engine system modeling. The side load physics captured in the low aspect-ratio, two-dimensional planar nozzle include the Coanda effect, afterburning wave, and the associated lip free-shock oscillation. Results of parametric studies indicate that equivalence ratio, combustion and ramp rate affect the side load physics. The side load physics inferred in the high aspect-ratio, axisymmetric nozzle study include the afterburning wave; transition from free-shock to restricted-shock separation, reverting back to free-shock separation, and transforming to restricted-shock separation again; and lip restricted-shock oscillation. The Mach disk loci and wall pressure history studies reconfirm that combustion and the associated thermodynamic properties affect the formation and duration of the asymmetric flow.

Ares I and Ares I-X Stage Separation Aerodynamic Testing

NASA Technical Reports Server (NTRS)

Pinier, Jeremy T.; Niskey, Charles J.

2011-01-01

The aerodynamics of the Ares I crew launch vehicle (CLV) and Ares I-X flight test vehicle (FTV) during stage separation was characterized by testing 1%-scale models at the Arnold Engineering Development Center s (AEDC) von Karman Gas Dynamics Facility (VKF) Tunnel A at Mach numbers of 4.5 and 5.5. To fill a large matrix of data points in an efficient manner, an injection system supported the upper stage and a captive trajectory system (CTS) was utilized as a support system for the first stage located downstream of the upper stage. In an overall extremely successful test, this complex experimental setup associated with advanced postprocessing of the wind tunnel data has enabled the construction of a multi-dimensional aerodynamic database for the analysis and simulation of the critical phase of stage separation at high supersonic Mach numbers. Additionally, an extensive set of data from repeated wind tunnel runs was gathered purposefully to ensure that the experimental uncertainty would be accurately quantified in this type of flow where few historical data is available for comparison on this type of vehicle and where Reynolds-averaged Navier-Stokes (RANS) computational simulations remain far from being a reliable source of static aerodynamic data.

Electrolyte additive for improved battery performance

DOEpatents

Bellows, Richard J.; Kantner, Edward

1989-04-04

In one embodiment of the present invention, there is provided an electrochemical cell having a metal bromine couple. The cell includes an electrode structure on which to deposit the metal of the couple and a counterelectrode at which to generate bromine. A microporous membrane separates the electrode and counterelectrode. Importantly, the aqueous electrolyte comprises an aqueous metal bromide solution containing a water soluble bromine complexing agent capable of forming a water immiscible complex with bromine and an additive capable of decreasing the wettability of the microporous separators employed in such cells by such water immiscible bromine complexes.

An accurate proteomic quantification method: fluorescence labeling absolute quantification (FLAQ) using multidimensional liquid chromatography and tandem mass spectrometry.

PubMed

Liu, Junyan; Liu, Yang; Gao, Mingxia; Zhang, Xiangmin

2012-08-01

A facile proteomic quantification method, fluorescent labeling absolute quantification (FLAQ), was developed. Instead of using MS for quantification, the FLAQ method is a chromatography-based quantification in combination with MS for identification. Multidimensional liquid chromatography (MDLC) with laser-induced fluorescence (LIF) detection with high accuracy and tandem MS system were employed for FLAQ. Several requirements should be met for fluorescent labeling in MS identification: Labeling completeness, minimum side-reactions, simple MS spectra, and no extra tandem MS fragmentations for structure elucidations. A fluorescence dye, 5-iodoacetamidofluorescein, was finally chosen to label proteins on all cysteine residues. The fluorescent dye was compatible with the process of the trypsin digestion and MALDI MS identification. Quantitative labeling was achieved with optimization of reacting conditions. A synthesized peptide and model proteins, BSA (35 cysteines), OVA (five cysteines), were used for verifying the completeness of labeling. Proteins were separated through MDLC and quantified based on fluorescent intensities, followed by MS identification. High accuracy (RSD% < 1.58) and wide linearity of quantification (1-10(5) ) were achieved by LIF detection. The limit of quantitation for the model protein was as low as 0.34 amol. Parts of proteins in human liver proteome were quantified and demonstrated using FLAQ. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Implicit face prototype learning from geometric information.

PubMed

Or, Charles C-F; Wilson, Hugh R

2013-04-19

There is evidence that humans implicitly learn an average or prototype of previously studied faces, as the unseen face prototype is falsely recognized as having been learned (Solso & McCarthy, 1981). Here we investigated the extent and nature of face prototype formation where observers' memory was tested after they studied synthetic faces defined purely in geometric terms in a multidimensional face space. We found a strong prototype effect: The basic results showed that the unseen prototype averaged from the studied faces was falsely identified as learned at a rate of 86.3%, whereas individual studied faces were identified correctly 66.3% of the time and the distractors were incorrectly identified as having been learned only 32.4% of the time. This prototype learning lasted at least 1 week. Face prototype learning occurred even when the studied faces were further from the unseen prototype than the median variation in the population. Prototype memory formation was evident in addition to memory formation of studied face exemplars as demonstrated in our models. Additional studies showed that the prototype effect can be generalized across viewpoints, and head shape and internal features separately contribute to prototype formation. Thus, implicit face prototype extraction in a multidimensional space is a very general aspect of geometric face learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Generic multi-dimensional feature extraction method using multiobjective genetic programming.

PubMed

Zhang, Yang; Rockett, Peter I

2009-01-01

In this paper, we present a generic feature extraction method for pattern classification using multiobjective genetic programming. This not only evolves the (near-)optimal set of mappings from a pattern space to a multi-dimensional decision space, but also simultaneously optimizes the dimensionality of that decision space. The presented framework evolves vector-to-vector feature extractors that maximize class separability. We demonstrate the efficacy of our approach by making statistically-founded comparisons with a wide variety of established classifier paradigms over a range of datasets and find that for most of the pairwise comparisons, our evolutionary method delivers statistically smaller misclassification errors. At very worst, our method displays no statistical difference in a few pairwise comparisons with established classifier/dataset combinations; crucially, none of the misclassification results produced by our method is worse than any comparator classifier. Although principally focused on feature extraction, feature selection is also performed as an implicit side effect; we show that both feature extraction and selection are important to the success of our technique. The presented method has the practical consequence of obviating the need to exhaustively evaluate a large family of conventional classifiers when faced with a new pattern recognition problem in order to attain a good classification accuracy.

2D and 3D Models of Convective Turbulence and Oscillations in Intermediate-Mass Main-Sequence Stars

NASA Astrophysics Data System (ADS)

Guzik, Joyce Ann; Morgan, Taylor H.; Nelson, Nicholas J.; Lovekin, Catherine; Kitiashvili, Irina N.; Mansour, Nagi N.; Kosovichev, Alexander

2015-08-01

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the sun, using three separate approaches: 1) Applying the spherical 3D MHD ASH (Anelastic Spherical Harmonics) code to simulate the core convection and radiative zone. Our goal is to determine whether core convection can excite low-frequency gravity modes, and thereby explain the presence of low frequencies for some hybrid gamma Dor/delta Sct variables for which the envelope convection zone is too shallow for the convective blocking mechanism to drive g modes; 2) Using the 3D planar ‘StellarBox’ radiation hydrodynamics code to model the envelope convection zone and part of the radiative zone. Our goals are to examine the interaction of stellar pulsations with turbulent convection in the envelope, excitation of acoustic modes, and the role of convective overshooting; 3) Applying the ROTORC 2D stellar evolution and dynamics code to calculate evolution with a variety of initial rotation rates and extents of core convective overshooting. The nonradial adiabatic pulsation frequencies of these nonspherical models will be calculated using the 2D pulsation code NRO of Clement. We will present new insights into gamma Dor and delta Sct pulsations gained by multidimensional modeling compared to 1D model expectations.

Application of a multidimensional gas chromatography system with simultaneous mass spectrometric and flame ionization detection to the analysis of sandalwood oil.

PubMed

Sciarrone, Danilo; Costa, Rosaria; Ragonese, Carla; Tranchida, Peter Quinto; Tedone, Laura; Santi, Luca; Dugo, Paola; Dugo, Giovanni; Joulain, Daniel; Mondello, Luigi

2011-01-07

The production and trade of Indian sandalwood oil is strictly regulated, due to the impoverishment of the plantations; for such a reason, Australian sandalwood oil has been evaluated as a possible substitute of the Indian type. International directives report, for both the genuine essential oils, specific ranges for the sesquiterpene alcohols (santalols). In the present investigation, a multidimensional gas chromatographic system (MDGC), equipped with simultaneous flame ionization and mass spectrometric detection (FID/MS), has been successfully applied to the analysis of a series of sandalwood oils of different origin. A detailed description of the system utilized is reported. Three santalol isomers, (Z)-α-trans-bergamotol, (E,E)-farnesol, (Z)-nuciferol, epi-α-bisabolol and (Z)-lanceol have been quantified. LoD (MS) and LoQ (FID) values were determined for (E,E)-farnesol, used as representative of the oxygenated sesquiterpenic group, showing levels equal to 0.002% and 0.003%, respectively. A great advantage of the instrumental configuration herein discussed, is represented by the fact that identification and quantitation of target analytes are carried out in one step, without the need to perform two separate analyses. Copyright © 2010 Elsevier B.V. All rights reserved.

Joint evolution of multiple social traits: a kin selection analysis

PubMed Central

Brown, Sam P.; Taylor, Peter D.

2010-01-01

General models of the evolution of cooperation, altruism and other social behaviours have focused almost entirely on single traits, whereas it is clear that social traits commonly interact. We develop a general kin-selection framework for the evolution of social behaviours in multiple dimensions. We show that whenever there are interactions among social traits new behaviours can emerge that are not predicted by one-dimensional analyses. For example, a prohibitively costly cooperative trait can ultimately be favoured owing to initial evolution in other (cheaper) social traits that in turn change the cost–benefit ratio of the original trait. To understand these behaviours, we use a two-dimensional stability criterion that can be viewed as an extension of Hamilton's rule. Our principal example is the social dilemma posed by, first, the construction and, second, the exploitation of a shared public good. We find that, contrary to the separate one-dimensional analyses, evolutionary feedback between the two traits can cause an increase in the equilibrium level of selfish exploitation with increasing relatedness, while both social (production plus exploitation) and asocial (neither) strategies can be locally stable. Our results demonstrate the importance of emergent stability properties of multidimensional social dilemmas, as one-dimensional stability in all component dimensions can conceal multidimensional instability. PMID:19828549

A Structure-Based Distance Metric for High-Dimensional Space Exploration with Multi-Dimensional Scaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hyun Jung; McDonnell, Kevin T.; Zelenyuk, Alla

2014-03-01

Although the Euclidean distance does well in measuring data distances within high-dimensional clusters, it does poorly when it comes to gauging inter-cluster distances. This significantly impacts the quality of global, low-dimensional space embedding procedures such as the popular multi-dimensional scaling (MDS) where one can often observe non-intuitive layouts. We were inspired by the perceptual processes evoked in the method of parallel coordinates which enables users to visually aggregate the data by the patterns the polylines exhibit across the dimension axes. We call the path of such a polyline its structure and suggest a metric that captures this structure directly inmore » high-dimensional space. This allows us to better gauge the distances of spatially distant data constellations and so achieve data aggregations in MDS plots that are more cognizant of existing high-dimensional structure similarities. Our MDS plots also exhibit similar visual relationships as the method of parallel coordinates which is often used alongside to visualize the high-dimensional data in raw form. We then cast our metric into a bi-scale framework which distinguishes far-distances from near-distances. The coarser scale uses the structural similarity metric to separate data aggregates obtained by prior classification or clustering, while the finer scale employs the appropriate Euclidean distance.« less

Application of the multidimensional fatigue inventory (MFI-20) in cancer patients receiving radiotherapy.

PubMed Central

Smets, E. M.; Garssen, B.; Cull, A.; de Haes, J. C.

1996-01-01

In this paper the psychometric properties of the multidimensional fatigue inventory (MFI-20) are established further in cancer patients. The MFI is a 20-item self-report instrument designed to measure fatigue. It covers the following dimensions: general fatigue, physical fatigue, reduced activity, reduced motivation and mental fatigue. The instrument was used in a Dutch and Scottish sample of cancer patients receiving radiotherapy. The dimensional structure was assessed using confirmatory factor analyses (Lisrel's unweighted least-squares method). The hypothesised five-factor model appeared to fit the data in both samples (adjusted goodness of fit; AGFI: 0.97 and 0.98). Internal consistency of the separate scales was good in both the Dutch and Scottish samples with Cronbach's alpha coefficients ranging from 0.79 to 0.93. Construct validity was assessed by correlating the MFI-20 to activities of daily living, anxiety and depression. Significant relations were assumed. Convergent validity was investigated by correlating the MFI scales with a visual analogue scale measuring fatigue and with a fatigue-scale derived from the Rotterdam Symptom Checklist. Results support the validity of the MFI-20. The highly similar results in the Dutch and Scottish sample suggest that the portrayal of fatigue using the MFI-20 is quite robust. PMID:8546913

Multidimensional assessment of self-regulated learning with middle school math students.

PubMed

Callan, Gregory L; Cleary, Timothy J

2018-03-01

This study examined the convergent and predictive validity of self-regulated learning (SRL) measures situated in mathematics. The sample included 100 eighth graders from a diverse, urban school district. Four measurement formats were examined including, 2 broad-based (i.e., self-report questionnaire and teacher ratings) and 2 task-specific measures (i.e., SRL microanalysis and behavioral traces). Convergent validity was examined across task-difficulty, and the predictive validity was examined across 3 mathematics outcomes: 2 measures of mathematical problem solving skill (i.e., practice session math problems, posttest math problems) and a global measure of mathematical skill (i.e., standardized math test). Correlation analyses were used to examine convergent validity and revealed medium correlations between measures within the same category (i.e., broad-based or task-specific). Relations between measurement classes were not statistically significant. Separate regressions examined the predictive validity of the SRL measures. While controlling all other predictors, a SRL microanalysis metacognitive-monitoring measure emerged as a significant predictor of all 3 outcomes and teacher ratings accounted for unique variance on 2 of the outcomes (i.e., posttest math problems and standardized math test). Results suggest that a multidimensional assessment approach should be considered by school psychologists interested in measuring SRL. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Collapse of resilience patterns in generalized Lotka-Volterra dynamics and beyond.

PubMed

Tu, Chengyi; Grilli, Jacopo; Schuessler, Friedrich; Suweis, Samir

2017-06-01

Recently, a theoretical framework aimed at separating the roles of dynamics and topology in multidimensional systems has been developed [Gao et al., Nature (London) 530, 307 (2016)10.1038/nature16948]. The validity of their method is assumed to hold depending on two main hypotheses: (i) The network determined by the the interaction between pairs of nodes has negligible degree correlations; (ii) the node activities are uniform across nodes on both the drift and the pairwise interaction functions. Moreover, the authors consider only positive (mutualistic) interactions. Here we show the conditions proposed by Gao and collaborators [Nature (London) 530, 307 (2016)10.1038/nature16948] are neither sufficient nor necessary to guarantee that their method works in general and validity of their results are not independent of the model chosen within the class of dynamics they considered. Indeed we find that a new condition poses effective limitations to their framework and we provide quantitative predictions of the quality of the one-dimensional collapse as a function of the properties of interaction networks and stable dynamics using results from random matrix theory. We also find that multidimensional reduction may work also for an interaction matrix with a mixture of positive and negative signs, opening up an application of the framework to food webs, neuronal networks, and social and economic interactions.

Collapse of resilience patterns in generalized Lotka-Volterra dynamics and beyond

NASA Astrophysics Data System (ADS)

Tu, Chengyi; Grilli, Jacopo; Schuessler, Friedrich; Suweis, Samir

2017-06-01

Recently, a theoretical framework aimed at separating the roles of dynamics and topology in multidimensional systems has been developed [Gao et al., Nature (London) 530, 307 (2016), 10.1038/nature16948]. The validity of their method is assumed to hold depending on two main hypotheses: (i) The network determined by the the interaction between pairs of nodes has negligible degree correlations; (ii) the node activities are uniform across nodes on both the drift and the pairwise interaction functions. Moreover, the authors consider only positive (mutualistic) interactions. Here we show the conditions proposed by Gao and collaborators [Nature (London) 530, 307 (2016), 10.1038/nature16948] are neither sufficient nor necessary to guarantee that their method works in general and validity of their results are not independent of the model chosen within the class of dynamics they considered. Indeed we find that a new condition poses effective limitations to their framework and we provide quantitative predictions of the quality of the one-dimensional collapse as a function of the properties of interaction networks and stable dynamics using results from random matrix theory. We also find that multidimensional reduction may work also for an interaction matrix with a mixture of positive and negative signs, opening up an application of the framework to food webs, neuronal networks, and social and economic interactions.

Chemical separation of Nd from geological samples for chronological studies using (146)Sm-(142)Nd and (147)Sm-(143)Nd systematics.

PubMed

Kagami, Saya; Yokoyama, Tetsuya

2016-09-21

Sm-Nd dating, which involves long-lived (147)Sm-(143)Nd and short-lived (146)Sm-(142)Nd systematics, has been widely used in the field of geosciences. To obtain precise and accurate ages of geological samples, the determination of highly precise Nd isotope ratios with nearly complete removal of Ce and Sm is indispensable to avoid mass spectral interference. In this study, we developed a three-step column chemistry procedure for separating Nd from geological samples that includes cation exchange chromatography for separating major elements from rare earth elements (REEs), oxidative extraction chromatography using Ln Resin coupled with HNO3 + KBrO3 for separating tetravalent Ce from the remaining REEs, and final purification of Nd using Ln Resin. This method enables high recovery of Nd (>91%) with effective separation of Nd from Ce and Sm (Ce/Nd < 1.2 × 10(-5) and Sm/Nd < 5.2 × 10(-6)). In addition, we devised a new method for determining Sm/Nd ratios with the isotope dilution inductively coupled plasma mass spectrometry method using (145)Nd- and (149)Sm-enriched spikes coupled with a group separation of REEs using TRU Resin. Applying the techniques developed in this study, we determined the Sm-Nd whole-rock isochron age of basaltic eucrites, yielding 4577 - 88(+ 55) Ma and 4558 ± 300 Ma for (146)Sm-(142)Nd and (147)Sm-(143)Nd systematics, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Sharing Roles, Sharing Custody? Couples' Characteristics and Children's Living Arrangements at Separation

ERIC Educational Resources Information Center

Juby, Heather; Le Bourdais, Celine; Marcil-Gratton, Nicole

2005-01-01

This article examines children's living arrangements when parents separate, during a period of rapid increase in shared physical custody in the 1990s. With prospective data from the National Longitudinal Survey of Children and Youth (N= 758 families) and a sample of families experiencing parental separation between successive survey cycles, we use…

An introduction to multidimensional measurement using Rasch models.

PubMed

Briggs, Derek C; Wilson, Mark

2003-01-01

The act of constructing a measure requires a number of important assumptions. Principle among these assumptions is that the construct is unidimensional. In practice there are many instances when the assumption of unidimensionality does not hold, and where the application of a multidimensional measurement model is both technically appropriate and substantively advantageous. In this paper we illustrate the usefulness of a multidimensional approach to measurement with the Multidimensional Random Coefficient Multinomial Logit (MRCML) model, an extension of the unidimensional Rasch model. An empirical example is taken from a collection of embedded assessments administered to 541 students enrolled in middle school science classes with a hands-on science curriculum. Student achievement on these assessments are multidimensional in nature, but can also be treated as consecutive unidimensional estimates, or as is most common, as a composite unidimensional estimate. Structural parameters are estimated for each model using ConQuest, and model fit is compared. Student achievement in science is also compared across models. The multidimensional approach has the best fit to the data, and provides more reliable estimates of student achievement than under the consecutive unidimensional approach. Finally, at an interpretational level, the multidimensional approach may well provide richer information to the classroom teacher about the nature of student achievement.

Morphological identification of Lucilia sericata, Lucilia cuprina and their hybrids (Diptera, Calliphoridae)

PubMed Central

Williams, Kirstin A.; Villet, Martin H.

2014-01-01

Abstract Hybrids of Lucilia sericata and Lucilia cuprina have been shown to exist in previous studies using molecular methods, but no study has shown explicitly that these hybrids can be identified morphologically. Published morphological characters used to identify L. sericata and L. cuprina were reviewed, and then scored and tested using specimens of both species and known hybrids. Ordination by multi-dimensional scaling indicated that the species were separable, and that hybrids resembled L. cuprina, whatever their origin. Discriminant function analysis of the characters successfully separated the specimens into three unambiguous groups – L. sericata, L. cuprina and hybrids. The hybrids were morphologically similar irrespective of whether they were from an ancient introgressed lineage or more modern. This is the first evidence that hybrids of these two species can be identified from their morphology. The usefulness of the morphological characters is also discussed and photographs of several characters are included to facilitate their assessment. PMID:25061373

Simultaneous generation of sub-5-femtosecond 400  nm and 800  nm pulses for attosecond extreme ultraviolet pump-probe spectroscopy.

PubMed

Chang, Hung-Tzu; Zürch, Michael; Kraus, Peter M; Borja, Lauren J; Neumark, Daniel M; Leone, Stephen R

2016-11-15

Few-cycle laser pulses with wavelengths centered at 400 nm and 800 nm are simultaneously obtained through wavelength separation of ultrashort, spectrally broadened Vis-NIR laser pulses spanning 350-1100 nm wavelengths. The 400 nm and 800 nm pulses are separately compressed, yielding pulses with 4.4 fs and 3.8 fs duration, respectively. The pulse energy exceeds 5 μJ for the 400 nm pulses and 750 μJ for the 800 nm pulses. Intense 400 nm few-cycle pulses have a broad range of applications in nonlinear optical spectroscopy, which include the study of photochemical dynamics, semiconductors, and photovoltaic materials on few-femtosecond to attosecond time scales. The ultrashort 400 nm few-cycle pulses generated here not only extend the spectral range of the optical pulse for NIR-XUV attosecond pump-probe spectroscopy but also pave the way for two-color, three-pulse, multidimensional optical-XUV spectroscopy experiments.

2Q NMR of 2H2O ordering at solid interfaces

NASA Astrophysics Data System (ADS)

Krivokhizhina, Tatiana V.; Wittebort, R. J.

2014-06-01

Solvent ordering at an interface can be studied by multiple-quantum NMR. Quantitative studies of 2H2O ordering require clean double-quantum (2Q) filtration and an analysis of 2Q buildup curves that accounts for relaxation and, if randomly oriented samples are used, the distribution of residual couplings. A pulse sequence with absorption mode detection is extended for separating coherences by order and measuring relaxation times such as the 2Q filtered T2. Coherence separation is used to verify 2Q filtration and the 2Q filtered T2 is required to extract the coupling from the 2Q buildup curve when it is unresolved. With our analysis, the coupling extracted from the buildup curve in 2H2O hydrated collagen was equivalent to the resolved coupling measured in the usual 1D experiment and the 2Q to 1Q signal ratio was in accord with theory. Application to buildup curves from 2H2O hydrated elastin, which has an unresolved coupling, revealed a large increase in the 2Q signal upon mechanical stretch that is due to an increase in the ordered water fraction while changes in the residual coupling and T2 are small.

A discrete Fourier-encoded, diagonal-free experiment to simplify homonuclear 2D NMR correlations.

PubMed

Huang, Zebin; Guan, Quanshuai; Chen, Zhong; Frydman, Lucio; Lin, Yulan

2017-07-21

Nuclear magnetic resonance (NMR) spectroscopy has long served as an irreplaceable, versatile tool in physics, chemistry, biology, and materials sciences, owing to its ability to study molecular structure and dynamics in detail. In particular, the connectivity of chemical sites within molecules, and thereby molecular structure, becomes visible by multi-dimensional NMR. Homonuclear correlation experiments are a powerful tool for identifying coupled spins. Generally, diagonal peaks in these correlation spectra display the strongest intensities and do not offer any new information beyond the standard one-dimensional spectrum, whereas weaker, symmetrically placed cross peaks contain most of the coupling information. The cross peaks near the diagonal are often affected by the tails of strong diagonal peaks or even obscured entirely by the diagonal. In this paper, we demonstrate a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks and combine it with a site-selective sculpting scheme, capable of simplifying the patterns arising in these 2D correlation spectra. The theoretical principles of the new methods are laid out, and experimental observations are rationalized on the basis of theoretical analyses. The ensuing techniques provide a new way to retrieve 2D coupling information within homonuclear spin systems, with enhanced sensitivity, speed, and clarity.

A discrete Fourier-encoded, diagonal-free experiment to simplify homonuclear 2D NMR correlations

NASA Astrophysics Data System (ADS)

Huang, Zebin; Guan, Quanshuai; Chen, Zhong; Frydman, Lucio; Lin, Yulan

2017-07-01

Nuclear magnetic resonance (NMR) spectroscopy has long served as an irreplaceable, versatile tool in physics, chemistry, biology, and materials sciences, owing to its ability to study molecular structure and dynamics in detail. In particular, the connectivity of chemical sites within molecules, and thereby molecular structure, becomes visible by multi-dimensional NMR. Homonuclear correlation experiments are a powerful tool for identifying coupled spins. Generally, diagonal peaks in these correlation spectra display the strongest intensities and do not offer any new information beyond the standard one-dimensional spectrum, whereas weaker, symmetrically placed cross peaks contain most of the coupling information. The cross peaks near the diagonal are often affected by the tails of strong diagonal peaks or even obscured entirely by the diagonal. In this paper, we demonstrate a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks and combine it with a site-selective sculpting scheme, capable of simplifying the patterns arising in these 2D correlation spectra. The theoretical principles of the new methods are laid out, and experimental observations are rationalized on the basis of theoretical analyses. The ensuing techniques provide a new way to retrieve 2D coupling information within homonuclear spin systems, with enhanced sensitivity, speed, and clarity.

Experimental heat and mass transfer of the separated and coupled rotating desiccant wheel and heat wheel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enteria, Napoleon; Yoshino, Hiroshi; Mochida, Akashi

The experimental evaluation of the separated and coupled rotating desiccant wheel and heat wheel is reported. The study aims to investigate the performance of the desiccant wheel and of the heat wheel both when operated separately and jointly. The performance evaluation of the desiccant wheel is based on its moisture removal capacity (MRC), moisture removal regeneration (MRR), and moisture mass balance (MMB). In addition, the study used the total energy balance (TEB), sensible coefficient of performance (COP{sub Sensible}), latent coefficient of performance (COP{sub Latent}) and, total coefficient of performance (COP{sub Total}). The performance of the heat wheel is based onmore » its effectiveness. The COP{sub Sensible}, COP{sub Latent} and, COP{sub Total} are used in the performance evaluation of the coupled desiccant wheel and heat wheel. The general results of the study show that the MRC, MRR and MMB coupled with the TEB, COP{sub Latent}, COP{sub Sensible} and COP{sub Total} predict adequately the performance of the desiccant wheel. In addition, the coupled operation of the desiccant wheel and heat wheel, contributed to the reduction of the external thermal energy requirement for the regeneration of the desiccant wheel. This study can be applied in other researches seeking evaluation of the desiccant wheel, heat wheel, and their combined operation. Moreover, the data presented here are significant for the desiccant wheel benchmarking and for evaluation of the desiccant wheel models. (author)« less

Waveguide coupling in the few-cycle regime

NASA Astrophysics Data System (ADS)

Leblond, Hervé; Terniche, Said

2016-04-01

We consider the coupling of two optical waveguides in the few-cycle regime. The analysis is performed in the frame of a generalized Kadomtsev-Petviashvili model. A set of two coupled modified Korteweg-de Vries equations is derived, and it is shown that three types of coupling can occur, involving the linear index, the dispersion, or the nonlinearity. The linear nondispersive coupling is investigated numerically, showing the formation of vector solitons. Separate pulses may be trapped together if they have not initially the same location, size, or phase, and even if their initial frequencies differ.

The Tunneling Method for Global Optimization in Multidimensional Scaling.

ERIC Educational Resources Information Center

Groenen, Patrick J. F.; Heiser, Willem J.

1996-01-01

A tunneling method for global minimization in multidimensional scaling is introduced and adjusted for multidimensional scaling with general Minkowski distances. The method alternates a local search step with a tunneling step in which a different configuration is sought with the same STRESS implementation. (SLD)

Multidimensional Poverty and Health Status as a Predictor of Chronic Income Poverty.

PubMed

Callander, Emily J; Schofield, Deborah J

2015-12-01

Longitudinal analysis of Wave 5 to 10 of the nationally representative Household, Income and Labour Dynamics in Australia dataset was undertaken to assess whether multidimensional poverty status can predict chronic income poverty. Of those who were multidimensionally poor (low income plus poor health or poor health and insufficient education attainment) in 2007, and those who were in income poverty only (no other forms of disadvantage) in 2007, a greater proportion of those in multidimensional poverty continued to be in income poverty for the subsequent 5 years through to 2012. People who were multidimensionally poor in 2007 had 2.17 times the odds of being in income poverty each year through to 2012 than those who were in income poverty only in 2005 (95% CI: 1.23-3.83). Multidimensional poverty measures are a useful tool for policymakers to identify target populations for policies aiming to improve equity and reduce chronic disadvantage. Copyright © 2014 John Wiley & Sons, Ltd.

Multidimensional upwind hydrodynamics on unstructured meshes using graphics processing units - I. Two-dimensional uniform meshes

NASA Astrophysics Data System (ADS)

Paardekooper, S.-J.

2017-08-01

We present a new method for numerical hydrodynamics which uses a multidimensional generalization of the Roe solver and operates on an unstructured triangular mesh. The main advantage over traditional methods based on Riemann solvers, which commonly use one-dimensional flux estimates as building blocks for a multidimensional integration, is its inherently multidimensional nature, and as a consequence its ability to recognize multidimensional stationary states that are not hydrostatic. A second novelty is the focus on graphics processing units (GPUs). By tailoring the algorithms specifically to GPUs, we are able to get speedups of 100-250 compared to a desktop machine. We compare the multidimensional upwind scheme to a traditional, dimensionally split implementation of the Roe solver on several test problems, and we find that the new method significantly outperforms the Roe solver in almost all cases. This comes with increased computational costs per time-step, which makes the new method approximately a factor of 2 slower than a dimensionally split scheme acting on a structured grid.

An advanced process-based distributed model for the investigation of rainfall-induced landslides: The effect of process representation and boundary conditions

NASA Astrophysics Data System (ADS)

Anagnostopoulos, Grigorios G.; Fatichi, Simone; Burlando, Paolo

2015-09-01

Extreme rainfall events are the major driver of shallow landslide occurrences in mountainous and steep terrain regions around the world. Subsurface hydrology has a dominant role on the initiation of rainfall-induced shallow landslides, since changes in the soil water content affect significantly the soil shear strength. Rainfall infiltration produces an increase of soil water potential, which is followed by a rapid drop in apparent cohesion. Especially on steep slopes of shallow soils, this loss of shear strength can lead to failure even in unsaturated conditions before positive water pressures are developed. We present HYDROlisthisis, a process-based model, fully distributed in space with fine time resolution, in order to investigate the interactions between surface and subsurface hydrology and shallow landslides initiation. Fundamental elements of the approach are the dependence of shear strength on the three-dimensional (3-D) field of soil water potential, as well as the temporal evolution of soil water potential during the wetting and drying phases. Specifically, 3-D variably saturated flow conditions, including soil hydraulic hysteresis and preferential flow phenomena, are simulated for the subsurface flow, coupled with a surface runoff routine based on the kinematic wave approximation. The geotechnical component of the model is based on a multidimensional limit equilibrium analysis, which takes into account the basic principles of unsaturated soil mechanics. A series of numerical simulations were carried out with various boundary conditions and using different hydrological and geotechnical components. Boundary conditions in terms of distributed soil depth were generated using both empirical and process-based models. The effect of including preferential flow and soil hydraulic hysteresis was tested together with the replacement of the infinite slope assumption with the multidimensional limit equilibrium analysis. The results show that boundary conditions play a crucial role in the model performance and that the introduced hydrological (preferential flow and soil hydraulic hysteresis) and geotechnical components (multidimensional limit equilibrium analysis) significantly improve predictive capabilities in the presented case study.

ANALYSIS OF ESSENTIAL NUCLEAR REACTOR MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodden, C.J.

1964-01-01

This book is intended as a laboratory reference tool. The separate book chapters have been written by workers in the various fields covered, with a couple written by the contributing editor, Clement J. Rodden. The chapters were abstracted separately for the database.

Physical, Chemical, Bibological, and Biotechnological sciences are incomplete without each other

USDA-ARS?s Scientific Manuscript database

By coupling of mechanics, optics, and mathematics, Theodor Svedberg invented the ultracentrifuge, which allowed separation of important biological materials by high centrifugal force, resulting in physical chemical separation and characterization of atherogenic low density lipoproteins and other bio...

20 CFR 234.21 - Definitions of “living with” and “living in the same household.”

Code of Federal Regulations, 2010 CFR

2010-04-01

...” if they lived together as a married couple in the same residence. However, an employee and spouse... married couple was living apart temporarily, if the separation was caused by circumstances beyond their...

Enhancing Student Motivation and Engagement: The Effects of a Multidimensional Intervention

ERIC Educational Resources Information Center

Martin, Andrew J.

2008-01-01

The present study sought to investigate the effects of a multidimensional educational intervention on high school students' motivation and engagement. The intervention incorporated: (a) multidimensional targets of motivation and engagement, (b) empirically derived intervention methodology, (c) research-based risk and protective factors, (d)…

Multidimensional effects in the thermal response of fuel rod simulators. [PWR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dabbs, R.D.; Ott, L.J.

1980-01-01

One of the primary objectives of the Oak Ridge National Laboratory Pressurized-Water Reactor Blowdown Heat Transfer Separate-Effects Program is the determination of the transient surface temperature and surface heat flux of fuel pin simulators (FPSs) from internal thermocouple signals obtained during a loss-of-coolant experiment (LOCE) in the Thermal-Hydraulics Test Facility. This analysis requires the solution of the classical inverse heat conduction problem. The assumptions that allow the governing differential equation to be reduced to one dimension can introduce significant errors in the computed surface heat flux and surface temperature. The degree to which these computed variables are perturbed is addressedmore » and quantified.« less

Canonical forms of multidimensional steady inviscid flows

NASA Technical Reports Server (NTRS)

Taasan, Shlomo

1993-01-01

Canonical forms and canonical variables for inviscid flow problems are derived. In these forms the components of the system governed by different types of operators (elliptic and hyperbolic) are separated. Both the incompressible and compressible cases are analyzed, and their similarities and differences are discussed. The canonical forms obtained are block upper triangular operator form in which the elliptic and non-elliptic parts reside in different blocks. The full nonlinear equations are treated without using any linearization process. This form enables a better analysis of the equations as well as better numerical treatment. These forms are the analog of the decomposition of the one dimensional Euler equations into characteristic directions and Riemann invariants.

Associations between Relational Pronoun Usage and the Quality of Early Family Interactions.

PubMed

Galdiolo, Sarah; Roskam, Isabelle; Verhofstadt, Lesley L; De Mol, Jan; Dewinne, Laura; Vandaudenard, Sylvain

2016-01-01

Our study examined the relationships of relational pronouns used in parental conversation to the quality of early family interactions, as indexed by Family Alliance (FA). We hypothesized that more positive family interactions were associated with the use of more we-pronouns (e.g., we, us, our; we-ness ) and fewer I- and you-pronouns (e.g., I, me, you, your; separateness ) by both mothers and fathers. Our statistical model using a multilevel modeling framework and two levels of analysis (i.e., a couple level and an individual level) was tested on 47 non-referred families ( n = 31 primiparous families; child's age, M = 15.75 months, SD = 2.73) with we-ness and separateness as outcomes and FA functions as between-dyads variables. Analyses revealed that we-ness within the parental couple was only positively associated with family affect sharing while separateness was negatively associated with different FA functions (e.g., communication mistakes). Our main finding suggested that the kinds of personal pronouns used by parental couples when discussing children's education would be associated to the emotional quality of the family interactions.

Associations between Relational Pronoun Usage and the Quality of Early Family Interactions

PubMed Central

Galdiolo, Sarah; Roskam, Isabelle; Verhofstadt, Lesley L.; De Mol, Jan; Dewinne, Laura; Vandaudenard, Sylvain

2016-01-01

Our study examined the relationships of relational pronouns used in parental conversation to the quality of early family interactions, as indexed by Family Alliance (FA). We hypothesized that more positive family interactions were associated with the use of more we-pronouns (e.g., we, us, our; we-ness) and fewer I- and you-pronouns (e.g., I, me, you, your; separateness) by both mothers and fathers. Our statistical model using a multilevel modeling framework and two levels of analysis (i.e., a couple level and an individual level) was tested on 47 non-referred families (n = 31 primiparous families; child’s age, M = 15.75 months, SD = 2.73) with we-ness and separateness as outcomes and FA functions as between-dyads variables. Analyses revealed that we-ness within the parental couple was only positively associated with family affect sharing while separateness was negatively associated with different FA functions (e.g., communication mistakes). Our main finding suggested that the kinds of personal pronouns used by parental couples when discussing children’s education would be associated to the emotional quality of the family interactions. PMID:27847495

Code Development in Coupled PARCS/RELAP5 for Supercritical Water Reactor

DOE PAGES

Hu, Po; Wilson, Paul

2014-01-01

The new capability is added to the existing coupled code package PARCS/RELAP5, in order to analyze SCWR design under supercritical pressure with the separated water coolant and moderator channels. This expansion is carried out on both codes. In PARCS, modification is focused on extending the water property tables to supercritical pressure, modifying the variable mapping input file and related code module for processing thermal-hydraulic information from separated coolant/moderator channels, and modifying neutronics feedback module to deal with the separated coolant/moderator channels. In RELAP5, modification is focused on incorporating more accurate water properties near SCWR operation/transient pressure and temperature in themore » code. Confirming tests of the modifications is presented and the major analyzing results from the extended codes package are summarized.« less

Separation of Be and Al for AMS using single-step column chromatography

NASA Astrophysics Data System (ADS)

Binnie, Steven A.; Dunai, Tibor J.; Voronina, Elena; Goral, Tomasz; Heinze, Stefan; Dewald, Alfred

2015-10-01

With the aim of simplifying AMS target preparation procedures for TCN measurements we tested a new extraction chromatography approach which couples an anion exchange resin (WBEC) to a chelating resin (Beryllium resin) to separate Be and Al from dissolved quartz samples. Results show that WBEC-Beryllium resin stacks can be used to provide high purity Be and Al separations using a combination of hydrochloric/oxalic and nitric acid elutions. 10Be and 26Al concentrations from quartz samples prepared using more standard procedures are compared with results from replicate samples prepared using the coupled WBEC-Beryllium resin approach and show good agreement. The new column procedure is performed in a single step, reducing sample preparation times relative to more traditional methods of TCN target production.

A Bistable Microelectronic Circuit for Sensing Extremely Low Electric Field

DTIC Science & Technology

2010-01-01

potential system describing the ferromagnetic ma- terials employed in the fluxgate magnetometers .1 To give a clearer picture of the separations between...this behavior in a specific prototype system comprised of three unidirectionally coupled ferromagnetic cores, the basis of a coupled core fluxgate ... magnetometer . Another prototypical quartic poten- tial based system of coupled overdamped Duffing elements has been applied to describe the dynamics

Agreement on Reporting of Physical, Psychological, and Sexual Violence among White, Black, and Hispanic Couples in the United States

ERIC Educational Resources Information Center

Caetano, Raul; Field, Craig; Ramisetty-Mikler, Suhasini; Lipsky, Sherry

2009-01-01

This article examines agreement on reports of male-to-female and female-to-male psychological, physical, and sexual violence among White, Black, and Hispanic couples in the United States. Using a probability sample, separate face-to-face interviews were conducted in respondents' homes with both members of 1,025 intact couples living in the 48…

Self-Sustained Ultrafast Pulsation in Coupled VCSELs

NASA Technical Reports Server (NTRS)

Ning, Cun-Zheng

2001-01-01

High frequency, narrow-band self-pulsating operation is demonstrated in two coupled vertical-cavity surface-emitting lasers (VCSELs). The coupled VCSELs provide an ideal source for high-repetition rate (over 40 GHz), sinusoidal-like modulated laser source with Gaussian-like near- and far-field profiles. We also show that the frequency of the modulation can be tuned by the inter-VCSEL separation or by DC-bias level.

Argentation chromatography coupled to ultrahigh-resolution mass spectrometry for the separation of a heavy crude oil.

PubMed

Molnárné Guricza, Lilla; Schrader, Wolfgang

2017-02-10

Simplification of highly complex mixtures such as crude oil by using chromatographic methods makes it possible to get more detailed information about the composition of the analyte. Separation by argentation chromatography can be achieved based on the interaction of different strength between the silver ions (Ag + ) immobilized through a spacer on the silica gel surface and the π-bonds of the analytes. Heavy crude oils contain compounds with a high number of heteroatoms (N, O, S) and a high degree of unsaturation thus making them the perfect analyte for argentation chromatography. The direct coupling of argentation chromatography and ultrahigh-resolution mass spectrometry allows to continuously tracking the separation of the many different compounds by retention time and allows sensitive detection on a molecular level. Direct injection of a heavy crude oil into a ultrahigh-resolution mass spectrometer showed components with DBE of up to 25, whereas analytes with DBE of up to 35 could be detected only after separation with argentation chromatography. The reduced complexity achieved by the separation helps increasing the information depth. Copyright © 2016. Published by Elsevier B.V.

Optimal design and evaluation of a color separation grating using rigorous coupled wave analysis

NASA Astrophysics Data System (ADS)

Nagayoshi, Mayumi; Oka, Keiko; Klaus, Werner; Komai, Yuki; Kodate, Kashiko

2006-02-01

In recent years, the technology which separates white light into the three primary colors of Red (R), Green (G) and Blue (B) and adjusts each optical intensity and composites R, G and B to display various colors is required in the development and spread of color visual equipments. Various color separation devices have been proposed and have been put to practical use in color visual equipments. We have focused on a small and light grating-type device which has the possibility of reduction in cost and large-scale production and generates only the three primary colors of R, G and B so that a high saturation level can be obtained. To perform a rigorous analysis and design of color separation gratings, our group has developed a program that is based on the Rigorous Coupled Wave Analysis (RCWA). We then calculated the parameters to obtain a diffraction efficiency of higher than 70% and the color gamut of about 70%. We will report on the design, fabrication and evaluation of color separation gratings that have been optimized for fabrication by laser drawing.

A multi-pathway model for photosynthetic reaction center

NASA Astrophysics Data System (ADS)

Qin, M.; Shen, H. Z.; Yi, X. X.

2016-03-01

Charge separation occurs in a pair of tightly coupled chlorophylls at the heart of photosynthetic reaction centers of both plants and bacteria. Recently it has been shown that quantum coherence can, in principle, enhance the efficiency of a solar cell, working like a quantum heat engine. Here, we propose a biological quantum heat engine (BQHE) motivated by Photosystem II reaction center (PSII RC) to describe the charge separation. Our model mainly considers two charge-separation pathways which is more than that typically considered in the published literature. We explore how these cross-couplings increase the current and power of the charge separation and discuss the effects of multiple pathways in terms of current and power. The robustness of the BQHE against the charge recombination in natural PSII RC and dephasing induced by environments is also explored, and extension from two pathways to multiple pathways is made. These results suggest that noise-induced quantum coherence helps to suppress the influence of acceptor-to-donor charge recombination, and besides, nature-mimicking architectures with engineered multiple pathways for charge separations might be better for artificial solar energy devices considering the influence of environments.

Heteronuclear Multidimensional Protein NMR in a Teaching Laboratory

ERIC Educational Resources Information Center

Wright, Nathan T.

2016-01-01

Heteronuclear multidimensional NMR techniques are commonly used to study protein structure, function, and dynamics, yet they are rarely taught at the undergraduate level. Here, we describe a senior undergraduate laboratory where students collect, process, and analyze heteronuclear multidimensional NMR experiments using an unstudied Ig domain (Ig2…

Compressed Continuous Computation v. 12/20/2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorodetsky, Alex

2017-02-17

A library for performing numerical computation with low-rank functions. The (C3) library enables performing continuous linear and multilinear algebra with multidimensional functions. Common tasks include taking "matrix" decompositions of vector- or matrix-valued functions, approximating multidimensional functions in low-rank format, adding or multiplying functions together, integrating multidimensional functions.

The Discriminating Power of Items that Measure More than One Dimension.

ERIC Educational Resources Information Center

Reckase, Mark D.

The work presented in this paper defined conceptually the concepts of multidimensional discrimination and information, derived mathematical expressions for the concepts for a particular multidimensional item response theory (IRT) model, and applied the concepts to actual test data. Multidimensional discrimination was defined as a function of the…

Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

ERIC Educational Resources Information Center

Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

2015-01-01

This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

Supervised and Unsupervised Learning of Multidimensional Acoustic Categories

ERIC Educational Resources Information Center

Goudbeek, Martijn; Swingley, Daniel; Smits, Roel

2009-01-01

Learning to recognize the contrasts of a language-specific phonemic repertoire can be viewed as forming categories in a multidimensional psychophysical space. Research on the learning of distributionally defined visual categories has shown that categories defined over 1 dimension are easy to learn and that learning multidimensional categories is…

Health, Wealth and Wisdom: Exploring Multidimensional Inequality in a Developing Country

ERIC Educational Resources Information Center

Nilsson, Therese

2010-01-01

Despite a broad theoretical literature on multidimensional inequality and a widespread belief that welfare is not synonymous to income--not the least in a developing context--empirical inequality examinations rarely includes several welfare attributes. We explore three techniques on how to evaluate multidimensional inequality using Zambian…

Multidimensional Physical Self-Concept of Athletes with Physical Disabilities

ERIC Educational Resources Information Center

Shapiro, Deborah R.; Martin, Jeffrey J.

2010-01-01

The purposes of this investigation were first to predict reported PA (physical activity) behavior and self-esteem using a multidimensional physical self-concept model and second to describe perceptions of multidimensional physical self-concept (e.g., strength, endurance, sport competence) among athletes with physical disabilities. Athletes (N =…

Method of data mining including determining multidimensional coordinates of each item using a predetermined scalar similarity value for each item pair

DOEpatents

Meyers, Charles E.; Davidson, George S.; Johnson, David K.; Hendrickson, Bruce A.; Wylie, Brian N.

1999-01-01

A method of data mining represents related items in a multidimensional space. Distance between items in the multidimensional space corresponds to the extent of relationship between the items. The user can select portions of the space to perceive. The user also can interact with and control the communication of the space, focusing attention on aspects of the space of most interest. The multidimensional spatial representation allows more ready comprehension of the structure of the relationships among the items.

A Conceptual Model for Multidimensional Analysis of Documents

NASA Astrophysics Data System (ADS)

Ravat, Franck; Teste, Olivier; Tournier, Ronan; Zurlfluh, Gilles

Data warehousing and OLAP are mainly used for the analysis of transactional data. Nowadays, with the evolution of Internet, and the development of semi-structured data exchange format (such as XML), it is possible to consider entire fragments of data such as documents as analysis sources. As a consequence, an adapted multidimensional analysis framework needs to be provided. In this paper, we introduce an OLAP multidimensional conceptual model without facts. This model is based on the unique concept of dimensions and is adapted for multidimensional document analysis. We also provide a set of manipulation operations.

A review of snapshot multidimensional optical imaging: measuring photon tags in parallel

PubMed Central

Gao, Liang; Wang, Lihong V.

2015-01-01

Multidimensional optical imaging has seen remarkable growth in the past decade. Rather than measuring only the two-dimensional spatial distribution of light, as in conventional photography, multidimensional optical imaging captures light in up to nine dimensions, providing unprecedented information about incident photons’ spatial coordinates, emittance angles, wavelength, time, and polarization. Multidimensional optical imaging can be accomplished either by scanning or parallel acquisition. Compared with scanning-based imagers, parallel acquisition—also dubbed snapshot imaging—has a prominent advantage in maximizing optical throughput, particularly when measuring a datacube of high dimensions. Here, we first categorize snapshot multidimensional imagers based on their acquisition and image reconstruction strategies, then highlight the snapshot advantage in the context of optical throughput, and finally we discuss their state-of-the-art implementations and applications. PMID:27134340

A multidimensional subdiffusion model: An arbitrage-free market

NASA Astrophysics Data System (ADS)

Li, Guo-Hua; Zhang, Hong; Luo, Mao-Kang

2012-12-01

To capture the subdiffusive characteristics of financial markets, the subordinated process, directed by the inverse α-stale subordinator Sα(t) for 0 < α < 1, has been employed as the model of asset prices. In this article, we introduce a multidimensional subdiffusion model that has a bond and K correlated stocks. The stock price process is a multidimensional subdiffusion process directed by the inverse α-stable subordinator. This model describes the period of stagnation for each stock and the behavior of the dependency between multiple stocks. Moreover, we derive the multidimensional fractional backward Kolmogorov equation for the subordinated process using the Laplace transform technique. Finally, using a martingale approach, we prove that the multidimensional subdiffusion model is arbitrage-free, and also gives an arbitrage-free pricing rule for contingent claims associated with the martingale measure.

Progress in multi-dimensional upwind differencing

NASA Technical Reports Server (NTRS)

Vanleer, Bram

1992-01-01

Multi-dimensional upwind-differencing schemes for the Euler equations are reviewed. On the basis of the first-order upwind scheme for a one-dimensional convection equation, the two approaches to upwind differencing are discussed: the fluctuation approach and the finite-volume approach. The usual extension of the finite-volume method to the multi-dimensional Euler equations is not entirely satisfactory, because the direction of wave propagation is always assumed to be normal to the cell faces. This leads to smearing of shock and shear waves when these are not grid-aligned. Multi-directional methods, in which upwind-biased fluxes are computed in a frame aligned with a dominant wave, overcome this problem, but at the expense of robustness. The same is true for the schemes incorporating a multi-dimensional wave model not based on multi-dimensional data but on an 'educated guess' of what they could be. The fluctuation approach offers the best possibilities for the development of genuinely multi-dimensional upwind schemes. Three building blocks are needed for such schemes: a wave model, a way to achieve conservation, and a compact convection scheme. Recent advances in each of these components are discussed; putting them all together is the present focus of a worldwide research effort. Some numerical results are presented, illustrating the potential of the new multi-dimensional schemes.

Resonant Optical Circuits Based on Coupling Between Whispering Gallery Modes in Dielectric Microresonators

DTIC Science & Technology

2007-12-30

111111 (2006). 2. S.P. Ashili , V.N. Astratov, and E.C.H. Sykes, “The effects of inter-cavity separation on optical coupling in dielectric bispheres...chains of coupled spherical cavities,” Opt. Lett. 32, 409-411 (2007). 4. V.N. Astratov, and S.P. Ashili , “Percolation of light through whispering...Propagation via Whispering Gallery Modes in 3-D Networks of Coupled Spherical Cavities (Talk), V.N. Astratov, S.P. Ashili , and A.M. Kapitonov, in Frontiers in

A Pronoun Analysis of Couples' Support Transactions.

PubMed

Hinnekens, Céline; Lemmens, Gilbert; Vanhee, Gaëlle; Verhofstadt, Lesley

2016-01-01

The present study collected data about couples' level of relationship quality and their usage of pronouns that express we-ness or separateness in the context of support interactions. The sample consisted of 48 couples in a long-term relationship who provided questionnaire data and participated in two videotaped social support interaction tasks. Couples' videotaped interactions were subsequently coded for the number of personal pronouns-we-words (e.g., we, ours, ourselves) versus you and me-words (e.g., me, mine, you, yours)-used by both partners.

Magnetically Separable Fe3O4@DOPA-Pd: A Heterogeneous Catalyst for Aqueous Heck Reaction

EPA Science Inventory

Magnetically separable Fe3O4@DOPA-Pd catalyst has been synthesized via anchoring of palladium over dopamine-coated magnetite via non-covalent interaction and the catalyst is utilized for expeditious Heck coupling in aqueous media.

The finite element method in low speed aerodynamics

NASA Technical Reports Server (NTRS)

Baker, A. J.; Manhardt, P. D.

1975-01-01

The finite element procedure is shown to be of significant impact in design of the 'computational wind tunnel' for low speed aerodynamics. The uniformity of the mathematical differential equation description, for viscous and/or inviscid, multi-dimensional subsonic flows about practical aerodynamic system configurations, is utilized to establish the general form of the finite element algorithm. Numerical results for inviscid flow analysis, as well as viscous boundary layer, parabolic, and full Navier Stokes flow descriptions verify the capabilities and overall versatility of the fundamental algorithm for aerodynamics. The proven mathematical basis, coupled with the distinct user-orientation features of the computer program embodiment, indicate near-term evolution of a highly useful analytical design tool to support computational configuration studies in low speed aerodynamics.

A Gas-Kinetic Scheme for Multimaterial Flows and Its Application in Chemical Reaction

NASA Technical Reports Server (NTRS)

Lian, Yongsheng; Xu, Kun

1999-01-01

This paper concerns the extension of the multicomponent gas-kinetic BGK-type scheme to multidimensional chemical reactive flow calculations. In the kinetic model, each component satisfies its individual gas-kinetic BGK equation and the equilibrium states of both components are coupled in space and time due to the momentum and energy exchange in the course of particle collisions. At the same time, according to the chemical reaction rule one component can be changed into another component with the release of energy, where the reactant and product could have different gamma. Many numerical test cases are included in this paper, which show the robustness and accuracy of kinetic approach in the description of multicomponent reactive flows.

Multigrid Method for Modeling Multi-Dimensional Combustion with Detailed Chemistry

NASA Technical Reports Server (NTRS)

Zheng, Xiaoqing; Liu, Chaoqun; Liao, Changming; Liu, Zhining; McCormick, Steve

1996-01-01

A highly accurate and efficient numerical method is developed for modeling 3-D reacting flows with detailed chemistry. A contravariant velocity-based governing system is developed for general curvilinear coordinates to maintain simplicity of the continuity equation and compactness of the discretization stencil. A fully-implicit backward Euler technique and a third-order monotone upwind-biased scheme on a staggered grid are used for the respective temporal and spatial terms. An efficient semi-coarsening multigrid method based on line-distributive relaxation is used as the flow solver. The species equations are solved in a fully coupled way and the chemical reaction source terms are treated implicitly. Example results are shown for a 3-D gas turbine combustor with strong swirling inflows.

Two-Dimensional Self-Consistent Radio Frequency Plasma Simulations Relevant to the Gaseous Electronics Conference RF Reference Cell

PubMed Central

Lymberopoulos, Dimitris P.; Economou, Demetre J.

1995-01-01

Over the past few years multidimensional self-consistent plasma simulations including complex chemistry have been developed which are promising tools for furthering our understanding of reactive gas plasmas and for reactor design and optimization. These simulations must be benchmarked against experimental data obtained in well-characterized systems such as the Gaseous Electronics Conference (GEC) reference cell. Two-dimensional simulations relevant to the GEC Cell are reviewed in this paper with emphasis on fluid simulations. Important features observed experimentally, such as off-axis maxima in the charge density and hot spots of metastable species density near the electrode edges in capacitively-coupled GEC cells, have been captured by these simulations. PMID:29151756